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Records |
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Author |
Smeyers, R.; Milošević, M.V.; Covaci, L. |
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Title |
Strong gate-tunability of flat bands in bilayer graphene due to moiré encapsulation between hBN monolayers |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Nanoscale |
Abbreviated Journal |
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| |
Volume |
15 |
Issue  |
9 |
Pages |
4561-4569 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
When using hexagonal boron-nitride (hBN) as a substrate for graphene, the resulting moire pattern creates secondary Dirac points. By encapsulating a multilayer graphene within aligned hBN sheets the controlled moire stacking may offer even richer benefits. Using advanced tight-binding simulations on atomistically-relaxed heterostructures, here we show that the gap at the secondary Dirac point can be opened in selected moire-stacking configurations, and is independent of any additional vertical gating of the heterostructure. On the other hand, gating can broadly tune the gap at the principal Dirac point, and may thereby strongly compress the first moire mini-band in width against the moire-induced gap at the secondary Dirac point. We reveal that in hBN-encapsulated bilayer graphene this novel mechanism can lead to isolated bands flatter than 10 meV under moderate gating, hence presenting a convenient pathway towards electronically-controlled strongly-correlated states on demand. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000933052600001 |
Publication Date |
2023-02-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2040-3364; 2040-3372 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
6.7 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 6.7; 2023 IF: 7.367 |
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| |
Call Number |
UA @ admin @ c:irua:195249 |
Serial |
7340 |
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| Permanent link to this record |
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Author |
Scolfaro, D.; Finamor, M.; Trinchao, L.O.; Rosa, B.L.T.; Chaves, A.; Santos, P., V.; Iikawa, F.; Couto, O.D.D., Jr. |
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Title |
Acoustically driven stark effect in transition metal dichalcogenide monolayers |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Acs Nano |
Abbreviated Journal |
Acs Nano |
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| |
Volume |
15 |
Issue |
9 |
Pages |
15371-15380 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The Stark effect is one of the most efficient mechanisms to manipulate many-body states in nanostructured systems. In mono- and few-layer transition metal dichalcogenides, it has been successfully induced by optical and electric field means. Here, we tune the optical emission energies and dissociate excitonic states in MoSe2 monolayers employing the 220 MHz in-plane piezoelectric field carried by surface acoustic waves. We transfer the monolayers to high dielectric constant piezoelectric substrates, where the neutral exciton binding energy is reduced, allowing us to efficiently quench (above 90%) and red-shift the excitonic optical emissions. A model for the acoustically induced Stark effect yields neutral exciton and trion in-plane polarizabilities of 530 and 630 x 10(-5) meV/(kV/cm)(2), respectively, which are considerably larger than those reported for monolayers encapsulated in hexagonal boron nitride. Large in-plane polarizabilities are an attractive ingredient to manipulate and modulate multiexciton interactions in two-dimensional semiconductor nanostructures for optoelectronic applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000703553600129 |
Publication Date |
2021-08-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1936-0851 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
13.942 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: 13.942 |
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Call Number |
UA @ admin @ c:irua:182545 |
Serial |
7415 |
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| Permanent link to this record |
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Author |
Cadorim, L.R.; de Toledo, L.V.; Ortiz, W.A.; Berger, J.; Sardella, E. |
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Title |
Closed vortex state in three-dimensional mesoscopic superconducting films under an applied transport current |
Type |
A1 Journal article |
| |
Year |
2023 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
107 |
Issue |
9 |
Pages |
094515-94518 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
By using the full 3D generalized time-dependent Ginzbug-Landau equation, we study a long superconducting film of finite width and thickness under an applied transport current. We show that, for sufficiently large thickness, the vortices and the antivortices become curved before they annihilate each other. As they approach the center of the sample, their ends combine, producing a single closed vortex. We also determine the critical values of the thickness for which the closed vortex sets in for different values of the Ginzburg-Ladau parameter. Finally, we propose a model of how to detect a closed vortex experimentally. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000957055800002 |
Publication Date |
2023-03-20 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.7 |
Times cited |
|
Open Access |
Not_Open_Access |
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Notes |
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Approved |
Most recent IF: 3.7; 2023 IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:196079 |
Serial |
7673 |
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Author |
Ozaydin, H.D.; Sahin, H.; Senger, R.T.; Peeters, F.M. |
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Title |
Formation and diffusion characteristics of Pt clusters on Graphene, 1H-MoS2 and 1T-TaS2 |
Type |
A1 Journal article |
| |
Year |
2014 |
Publication |
Annalen der Physik |
Abbreviated Journal |
Ann Phys-Berlin |
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Volume |
526 |
Issue |
9-10 |
Pages |
423-429 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Many experiments have revealed that the surfaces of graphene and graphene-like structures can play an active role as a host surface for clusterization of transition metal atoms. Motivated by these observations, we investigate theoretically the adsorption, diffusion and magnetic properties of Pt clusters on three different two-dimensional atomic crystals using first principles density functional theory. We found that monolayers of graphene, molybdenum disulfide (1H-MoS2) and tantalum disulfide (1T-TaS2) provide different nucleation characteristics for Pt cluster formation. At low temperatures, while the bridge site is the most favorable site where the growth of a Pt cluster starts on graphene, top-Mo and top-Ta sites are preferred on 1H-MoS2 and 1T-TaS2, respectively. Ground state structures and magnetic properties of Pt-n clusters (n= 2,3,4) on three different monolayer crystal structures are obtained. We found that the formation of Pt-2 dimer and a triangle-shaped Pt-3 cluster perpendicular to the surface are favored over the three different surfaces. While bent rhombus shaped Pt-4 is formed on graphene, the formation of tetrahedral shaped clusters are more favorable on 1H-MoS2 and 1T-TaS2. Our study of the formation of Pt-n clusters on three different monolayers provides a gateway for further exploration of nanocluster formations on various surfaces. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Leipzig |
Editor |
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Language |
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Wos |
000343873700015 |
Publication Date |
2014-06-16 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0003-3804; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.039 |
Times cited |
10 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWO Pegasus Long Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.039; 2014 IF: 3.048 |
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Call Number |
UA @ lucian @ c:irua:121180 |
Serial |
1247 |
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| Permanent link to this record |
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Author |
Cangi, A.; Moldabekov, Z.A.; Neilson, D. |
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Title |
International Conference on “Strongly Coupled Coulomb Systems” (July 24-29, 2022, Görlitz, Germany) |
Type |
Editorial |
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Year |
2023 |
Publication |
Contributions to plasma physics |
Abbreviated Journal |
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Volume |
63 |
Issue |
9-10 |
Pages |
e202300110-3 |
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Keywords |
Editorial; Condensed Matter Theory (CMT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
001100083800001 |
Publication Date |
2023-11-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0863-1042; 1521-3986 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
|
Times cited |
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Open Access |
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Notes |
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Approved |
no |
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Call Number |
UA @ admin @ c:irua:201156 |
Serial |
9051 |
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Author |
Dantas, D.S.; Lima, A.R.P.; Chaves, A.; Almeida, C.A.S.; Farias, G.A.; Milošević, M.V. |
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Title |
Bound vortex states and exotic lattices in multicomponent Bose-Einstein condensates : the role of vortex-vortex interaction |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
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| |
Volume |
91 |
Issue |
91 |
Pages |
023630 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We numerically study the vortex-vortex interaction in multicomponent homogeneous Bose-Einstein condensates within the realm of the Gross-Pitaevskii theory. We provide strong evidence that pairwise vortex interaction captures the underlying mechanisms which determine the geometric configuration of the vortices, such as different lattices in many-vortex states, as well as the bound vortex states with two (dimer) or three (trimer) vortices. Specifically, we discuss and apply our theoretical approach to investigate intra- and intercomponent vortex-vortex interactions in two- and three-component Bose-Einstein condensates, thereby shedding light on the formation of the exotic vortex configurations. These results correlate with current experimental efforts in multicomponent Bose-Einstein condensates and the understanding of the role of vortex interactions in multiband superconductors. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000350255200014 |
Publication Date |
2015-02-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1050-2947;1094-1622; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.925 |
Times cited |
12 |
Open Access |
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Notes |
; This work was supported by the National Council for Scientific and Technological Development (CNPq-Brazil), the Coordination for the Improvement of Higher Education Personnel (CAPES-Brazil), Research Foundation Flanders (FWO), and the bilateral FWO-CNPq program between Flanders and Brazil. M.V.M. acknowledges support from the CAPES-PVE program (Grant No. BEX1392/11-5). ; |
Approved |
Most recent IF: 2.925; 2015 IF: 2.808 |
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Call Number |
c:irua:124907 |
Serial |
252 |
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| Permanent link to this record |
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Author |
Grujić, M.M.; Tadic, M.Z.; Peeters, F.M. |
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Title |
Chiral properties of topological-state loops |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
245432 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The angular momentum quantization of chiral gapless modes confined to a circularly shaped interface between two different topological phases is investigated. By examining several different setups, we show analytically that the angular momentum of the topological modes exhibits a highly chiral behavior, and can be coupled to spin and/or valley degrees of freedom, reflecting the nature of the interface states. A simple general one-dimensional model, valid for arbitrarily shaped loops, is shown to predict the corresponding energies and the magnetic moments. These loops can be viewed as building blocks for artificial magnets with tunable and highly diverse properties. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000356928200005 |
Publication Date |
2015-06-27 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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Notes |
; This work was supported by the Ministry of Education, Science and Technological Development (Serbia), and the Fonds Wetenschappelijk Onderzoek (Belgium). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:127039 |
Serial |
357 |
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| Permanent link to this record |
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Author |
Shylau, A.A.; Badalyan, S.M.; Peeters, F.M.; Jauho, A.P. |
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Title |
Electron polarization function and plasmons in metallic armchair graphene nanoribbons |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
205444 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Plasmon excitations in metallic armchair graphene nanoribbons are investigated using the random phase approximation. An exact analytical expression for the polarization function of Dirac fermions is obtained, valid for arbitrary temperature and doping. We find that at finite temperatures, due to the phase space redistribution among inter-band and intra-band electronic transitions in the conduction and valence bands, the full polarization function becomes independent of temperature and position of the chemical potential. It is shown that for a given width of nanoribbon there exists a single plasmon mode whose energy dispersion is determined by the graphene's fine structure constant. In the case of two Coulomb-coupled nanoribbons, this plasmon splits into in-phase and out-of-phase plasmon modes with splitting energy determined by the inter-ribbon spacing. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000355315400007 |
Publication Date |
2015-05-29 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
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Notes |
; The Center for Nanostructured Graphene (CNG) is sponsored by the Danish National Research Foundation (DNRF58). The work at the University of Antwerp was supported by the Flemisch Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. S.M.B. gratefully acknowledges hospitality and support from the Department of Physics at the University of Missouri. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:126403 |
Serial |
984 |
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| Permanent link to this record |
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Author |
Petrovic, M.D.; Peeters, F.M. |
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Title |
Fano resonances in the conductance of graphene nanoribbons with side gates |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
035444 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The control of side gates on the quantum electron transport in narrow graphene ribbons of different widths and edge types (armchair and zigzag) is investigated. The conductance exhibits Fano resonances with varying side gate potential. Resonant and antiresonant peaks in the conductance can be associated with the eigenstates of a closed system, and these peaks can be accurately fitted with a Fano line shape. The local density of states (LDOS) and the electron current show a specific behavior at these resonances, which depends on the ribbon edge type. In zigzag ribbons, transport is dominated by intervalley scattering, which is reflected in the transmission functions of individual modes. The side gates induce p-n interfaces near the edges at which the LDOS exhibits peaks. Near the resonance points, the electron current flows uniformly through the constriction, while near the antiresonances it creates vortices. In the armchair ribbons the LDOS spreads in areas of high potential, with current flowing near the edges. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000351217900005 |
Publication Date |
2015-01-30 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
17 |
Open Access |
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Notes |
; This work was supported by the Methusalem programme of the Flemish government. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:125422 |
Serial |
1172 |
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| Permanent link to this record |
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Author |
Schoelz, J.K.; Xu, P.; Meunier, V.; Kumar, P.; Neek-Amal, M.; Thibado, P.M.; Peeters, F.M. |
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Title |
Graphene ripples as a realization of a two-dimensional Ising model : a scanning tunneling microscope study |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review: B: condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
045413 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Ripples in pristine freestanding graphene naturally orient themselves in an array that is alternately curved-up and curved-down; maintaining an average height of zero. Using scanning tunneling microscopy (STM) to apply a local force, the graphene sheet will reversibly rise and fall in height until the height reaches 60%-70% of its maximum at which point a sudden, permanent jump occurs. We successfully model the ripples as a spin-half Ising magnetic system, where the height of the graphene plays the role of the spin. The permanent jump in height, controlled by the tunneling current, is found to be equivalent to an antiferromagnetic-to-ferromagnetic phase transition. The thermal load underneath the STM tip alters the local tension and is identified as the responsible mechanism for the phase transition. Four universal critical exponents are measured from our STM data, and the model provides insight into the statistical role of graphene's unusual negative thermal expansion coefficient. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000348762200011 |
Publication Date |
2015-01-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
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Notes |
; This work was supported in part by Office of Naval Research (USA) under Grant No. N00014-10-1-0181 and National Science Foundation (USA) under Grant No. DMR-0855358. F. M. Peeters and M. Neek-Amal were supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:123866 |
Serial |
1377 |
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| Permanent link to this record |
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Author |
Kuopanportti, P.; Orlova, N.V.; Milošević, M.V. |
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Title |
Ground-state multiquantum vortices in rotating two-species superfluids |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
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| |
Volume |
91 |
Issue |
91 |
Pages |
043605 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We show numerically that a rotating, harmonically trapped mixture of two Bose-Einstein-condensed superfluids cancontrary to its single-species counterpartcontain a multiply quantized vortex in the ground state of the system. This giant vortex can occur without any accompanying single-quantum vortices, may either be coreless or have an empty core, and can be realized in a Rb87−K41 Bose-Einstein condensate. Our results not only provide a rare example of a stable, solitary multiquantum vortex but also reveal exotic physics stemming from the coexistence of multiple, compositionally distinct condensates in one system. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000352255200005 |
Publication Date |
2015-04-07 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1050-2947;1094-1622; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.925 |
Times cited |
25 |
Open Access |
|
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| |
Notes |
; This work was supported by the Finnish Cultural Foundation, the Research Foundation – Flanders (FWO), and the Magnus Ehrnrooth Foundation. We thank E. Ruokokoski and T. P. Simula for valuable comments and discussions. ; |
Approved |
Most recent IF: 2.925; 2015 IF: 2.808 |
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| |
Call Number |
c:irua:124906 |
Serial |
1388 |
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| Permanent link to this record |
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Author |
Bacaksiz, C.; Sahin, H.; Ozaydin, H.D.; Horzum, S.; Senger, R.T.; Peeters, F.M. |
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| |
Title |
Hexagonal A1N : dimensional-crossover-driven band-gap transition |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
085430 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Motivated by a recent experiment that reported the successful synthesis of hexagonal (h) AlN [Tsipas et al., Appl. Phys. Lett. 103, 251605 (2013)], we investigate structural, electronic, and vibrational properties of bulk, bilayer, and monolayer structures of h-AlN by using first-principles calculations. We show that the hexagonal phase of the bulk h-AlN is a stable direct-band-gap semiconductor. The calculated phonon spectrum displays a rigid-layer shear mode at 274 cm(-1) and an E-g mode at 703 cm(-1), which are observable by Raman measurements. In addition, single-layer h-AlN is an indirect-band-gap semiconductor with a nonmagnetic ground state. For the bilayer structure, AA'-type stacking is found to be the most favorable one, and interlayer interaction is strong. While N-layered h-AlN is an indirect-band-gap semiconductor for N = 1 – 9, we predict that thicker structures (N >= 10) have a direct band gap at the Gamma point. The number-of-layer-dependent band-gap transitions in h-AlN is interesting in that it is significantly different from the indirect-to-direct crossover obtained in the transition-metal dichalcogenides. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000350319200020 |
Publication Date |
2015-02-27 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
99 |
Open Access |
|
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). C.B. and R.T.S. acknowledge the support from TUBITAK Project No 114F397. H.S. is supported by a FWO Pegasus Long Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:125416 |
Serial |
1421 |
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| Permanent link to this record |
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Author |
Van Boxem, R.; Partoens, B.; Verbeeck, J. |
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| |
Title |
Inelastic electron-vortex-beam scattering |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
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| |
Volume |
91 |
Issue |
91 |
Pages |
032703 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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| |
Abstract |
Recent theoretical and experimental developments in the field of electron-vortex-beam physics have raised questions about what exactly this novelty in the field of electron microscopy (and other fields, such as particle physics) really provides. An important part of the answer to these questions lies in scattering theory. The present investigation explores various aspects of inelastic quantum scattering theory for cylindrically symmetric beams with orbital angular momentum. The model system of Coulomb scattering on a hydrogen atom provides the setting to address various open questions: How is momentum transferred? Do vortex beams selectively excite atoms, and how can one employ vortex beams to detect magnetic transitions? The analytical approach presented here provides answers to these questions. OAM transfer is possible, but not through selective excitation; rather, by pre- and postselection one can filter out the relevant contributions to a specific signal. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
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Wos |
000351035000004 |
Publication Date |
2015-03-16 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1050-2947;1094-1622; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
2.925 |
Times cited |
31 |
Open Access |
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| |
Notes |
Fwo; 312483 Esteem2; 278510 Vortex; esteem2jra3 ECASJO; |
Approved |
Most recent IF: 2.925; 2015 IF: 2.808 |
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| |
Call Number |
c:irua:123925 c:irua:123925UA @ admin @ c:irua:123925 |
Serial |
1607 |
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| Permanent link to this record |
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Author |
Zha, G.-Q.; Covaci, L.; Peeters, F.M.; Zhou, S.-P. |
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Title |
Mixed pairing symmetries and flux-induced spin current in mesoscopic superconducting loops with spin correlations |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
214504 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We numerically investigate the mixed pairing symmetries inmesoscopic superconducting loops in the presence of spin correlations by solving the Bogoliubov-de Gennes equations self-consistently. The spatial variations of the superconducting order parameters and the spontaneous magnetization are determined by the band structure. When the threaded magnetic flux turns on, the charge and spin currents both emerge and depict periodic evolution. In the case of a mesoscopic loop with dominant triplet p(x) +/- ip(y)-wave symmetry, a slight change of the chemical potential may lead to novel flux-dependent evolution patterns of the ground-state energy and the magnetization. The spin-polarized currents show pronounced quantum oscillations with fractional periods due to the appearance of energy jumps in flux, accompanied with a steplike feature of the enhanced spin current. Particularly, at some appropriate flux, the peaks of the zero-energy local density of states clearly indicate the occurrence of the odd-frequency pairing. In the case of a superconducting loop with dominant singlet d(x2-y2)-wave symmetry, the spatial profiles of the zero-energy local density of states and the magnetization show spin-dependent features on different sample diagonals. Moreover, the evolution of the flux-induced spin current always exhibits an hc/e periodicity. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000355647100003 |
Publication Date |
2015-06-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
15 |
Open Access |
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| |
Notes |
; This work was supported by the National Natural Science Foundation of China under Grants No. 61371020 and No. 61271163, by the Visiting Scholar Program of Shanghai Municipal Education Commission, and by the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:126433 |
Serial |
2089 |
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| Permanent link to this record |
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Author |
Muñoz, W.A.; Covaci, L.; Peeters, F.M. |
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Title |
Disordered graphene Josephson junctions |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
054506 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A tight-binding approach based on the Chebyshev-Bogoliubov-de Gennes method is used to describe disordered single-layer graphene Josephson junctions. Scattering by vacancies, ripples, or charged impurities is included. We compute the Josephson current and investigate the nature of multiple Andreev reflections, which induce bound states appearing as peaks in the density of states for energies below the superconducting gap. In the presence of single-atom vacancies, we observe a strong suppression of the supercurrent, which is a consequence of strong intervalley scattering. Although lattice deformations should not induce intervalley scattering, we find that the supercurrent is still suppressed, which is due to the presence of pseudomagnetic barriers. For charged impurities, we consider two cases depending on whether the average doping is zero, i.e., existence of electron-hole puddles, or finite. In both cases, short-range impurities strongly affect the supercurrent, similar to the vacancies scenario. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000349436500001 |
Publication Date |
2015-02-06 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
7 |
Open Access |
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| |
Notes |
This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and the Methusalem funding of the Flemish Government. |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:129192 |
Serial |
3961 |
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| Permanent link to this record |
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Author |
Szaszko-Bogar, V.; Peeters, F.M.; Foeldi, P. |
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Title |
Oscillating spin-orbit interaction in two-dimensional superlattices : sharp transmission resonances and time-dependent spin-polarized currents |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
91 |
Issue |
91 |
Pages |
235311 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We consider ballistic transport through a lateral, two-dimensional superlattice with experimentally realizable, sinusoidally oscillating, Rashba-type spin-orbit interaction (SOI). The periodic structure of the rectangular lattice produces a spin-dependent miniband structure for static SOI. Using Floquet theory, transmission peaks are shown to appear in themini-bandgaps as a consequence of the additional, time-dependent SOI. A detailed analysis shows that this effect is due to the generation of harmonics of the driving frequency, via which, e.g., resonances that cannot be excited in the case of static SOI become available. Additionally, the transmitted current shows space-and time-dependent partial spin polarization, in other words, polarization waves propagate through the superlattice. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000355956500003 |
Publication Date |
2015-06-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
10 |
Open Access |
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| |
Notes |
; This work was partially supported by the European Union and the European Social Fund through Projects No. TAMOP-4.2.2.C-11/1/KONV-2012-0010 and No. TAMOP-4.2.2.A-11/1/KONV-2012-0060, and by the Hungarian Scientific Research Fund (OTKA) under Contracts No. T81364 and No. 116688. The ELI-ALPS Project (GOP-1.1.1-12/B-2012-0001) is supported by the European Union and cofinanced by the European Regional Development Fund. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:126432 |
Serial |
2534 |
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| Permanent link to this record |
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Author |
Aierken, Y.; Sahin, H.; Iyikanat, F.; Horzum, S.; Suslu, A.; Chen, B.; Senger, R.T.; Tongay, S.; Peeters, F.M. |
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Title |
Portlandite crystal : bulk, bilayer, and monolayer structures |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
245413 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Ca(OH)(2) crystals, well known as portlandite, are grown in layered form, and we found that they can be exfoliated on different substrates. We performed first principles calculations to investigate the structural, electronic, vibrational, and mechanical properties of bulk, bilayer, and monolayer structures of this material. Different from other lamellar structures such as graphite and transition-metal dichalcogenides, intralayer bonding in Ca(OH)(2) is mainly ionic, while the interlayer interaction remains a weak dispersion-type force. Unlike well-known transition-metal dichalcogenides that exhibit an indirect-to-direct band gap crossover when going from bulk to a single layer, Ca(OH)(2) is a direct band gap semiconductor independent of the number layers. The in-plane Young's modulus and the in-plane shear modulus of monolayer Ca(OH)(2) are predicted to be quite low while the in-plane Poisson ratio is larger in comparison to those in the monolayer of ionic crystal BN. We measured the Raman spectrum of bulk Ca(OH)(2) and identified the high-frequency OH stretching mode A(1g) at 3620 cm(-1). In this study, bilayer and monolayer portlandite [Ca(OH)(2)] are predicted to be stable and their characteristics are analyzed in detail. Our results can guide further research on ultrathin hydroxites. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000356135600007 |
Publication Date |
2015-06-12 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWO Pegasus Long Marie Curie Fellowship. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:126983 |
Serial |
2675 |
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| Permanent link to this record |
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Author |
Zalipaev, V.; Linton, C.M.; Croitoru, M.D.; Vagov, A. |
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Title |
Resonant tunneling and localized states in a graphene monolayer with a mass gap |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
085405 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study tunneling of quasiparticles through potential barriers in a graphene monolayer with the mass gap using a semiclassical (WKB) approach. The main equations are derived in away similar to the WKB theory for the Schrodinger equation, which allows for explicit solutions at all orders. The analog of the classical action is used to distinguish types of possible stationary states in the system. The analysis focuses on the resonant scattering and the hole states localized in the vicinity of a barrier that are often overlooked. The scattering coefficients for the physically interesting limits are obtained by matching the WKB approximation with the known solutions at turning points. The localized states demonstrate unconventional properties and lead to alterations of the single particle density of states. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000351773900004 |
Publication Date |
2015-02-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
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Notes |
; M.D.C. acknowledges the Belgian Science Policy (BELSPO Back to Belgium Grant). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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Call Number |
c:irua:125523 |
Serial |
2891 |
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| Permanent link to this record |
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Author |
Singh, S.K.; Neek-Amal, M.; Costamagna, S.; Peeters, F.M. |
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Title |
Rippling, buckling, and melting of single- and multilayer MoS2 |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
014101 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Large-scale atomistic simulations using the reactive empirical bond order force field approach is implemented to investigate thermal and mechanical properties of single-layer (SL) and multilayer (ML) molybdenum disulfide (MoS2). The amplitude of the intrinsic ripples of SL MoS2 are found to be smaller than those exhibited by graphene (GE). Furthermore, because of the van der Waals interaction between layers, the out-of-plane thermal fluctuations of ML MoS2 decreases rapidly with increasing number of layers. This trend is confirmed by the buckling transition due to uniaxial stress which occurs for a significantly larger applied tension as compared to graphene. For SL MoS2, the melting temperature is estimated to be 3700 K which occurs through dimerization followed by the formation of small molecules consisting of two to five atoms. When different types of vacancies are inserted in the SL MoS2 it results in a decrease of both the melting temperature as well as the stiffness. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000347921300001 |
Publication Date |
2015-01-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
40 |
Open Access |
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| |
Notes |
; This work is supported by the ESF-Eurographene project CONGRAN, the Flemish Science Foundation (FWO-VI), and the Methusalem Foundation of the Flemish Government. We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. We would like to thanks Prof. Douglas E. Spearot [26] for giving us the implemented parameters of Mo-S in LAMMPS. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:123834 |
Serial |
2909 |
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| Permanent link to this record |
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Author |
Leenaerts, O.; Schoeters, B.; Partoens, B. |
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Title |
Stable kagome lattices from group IV elements |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
115202 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A thorough investigation of three-dimensional kagome lattices of group IV elements is performed with first-principles calculations. The investigated kagome lattices of silicon and germanium are found to be of similar stability as the recently proposed carbon kagome lattice. Carbon and silicon kagome lattices are both direct-gap semiconductors but they have qualitatively different electronic band structures. While direct optical transitions between the valence and conduction bands are allowed in the carbon case, no such transitions can be observed for silicon. The kagome lattice of germanium exhibits semimetallic behavior but can be transformed into a semiconductor after compression. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000351900700003 |
Publication Date |
2015-03-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
12 |
Open Access |
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Notes |
; This work was supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Hercules Foundation and the Flemish Government – department EWI. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:125516 |
Serial |
3144 |
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| Permanent link to this record |
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Author |
Zhang, L.-F.; Covaci, L.; Peeters, F.M. |
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Title |
Tomasch effect in nanoscale superconductors |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
024508 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
The Tomasch effect (TE) is due to quasiparticle interference (QPI) as induced by a nonuniform superconducting order parameter, which results in oscillations in the density of states (DOS) at energies above the superconducting gap. Quantum confinement in nanoscale superconductors leads to an inhomogenerous distribution of the Cooperpair condensate, which, as we found, triggers the manifestation of a new TE. We investigate the electronic structure of nanoscale superconductors by solving the Bogoliubov-de Gennes (BdG) equations self-consistently and describe the TE determined by two types of processes, involving two-or three-subband QPIs. Both types of QPIs result in additional BCS-like Bogoliubov-quasiparticles and BCS-like energy gaps leading to oscillations in the DOS and modulated wave patterns in the local density of states. These effects are strongly related to the symmetries of the system. A reduced 4 x 4 inter-subband BdG Hamiltonian is established in order to describe analytically the TE of two-subband QPIs. Our study is relevant to nanoscale superconductors, either nanowires or thin films, Bose-Einsten condensates, and confined systems such as two-dimensional electron gas interface superconductivity. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
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Wos |
000348473700003 |
Publication Date |
2015-01-16 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and the Methusalem funding of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:123864 |
Serial |
3670 |
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| Permanent link to this record |
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Author |
Richardson, C.L.; Edkins, S.D.; Berdiyorov, G.R.; Chua, C.J.; Griffiths, J.P.; Jones, G.A.C.; Buitelaar, M.R.; Narayan, V.; Sfigakis, F.; Smith, C.G.; Covaci, L.; Connolly, M.R.; |
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| |
Title |
Vortex detection and quantum transport in mesoscopic graphene Josephson-junction arrays |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
245418 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We investigate mesoscopic Josephson-junction arrays created by patterning superconducting disks on monolayer graphene, concentrating on the high-T/T-c regime of these devices and the phenomena which contribute to the superconducting glass state in diffusive arrays. We observe features in the magnetoconductance at rational fractions of flux quanta per array unit cell, which we attribute to the formation of flux-quantized vortices. The applied fields at which the features occur are well described by Ginzburg-Landau simulations that take into account the number of unit cells in the array. We find that the mean conductance and universal conductance fluctuations are both enhanced below the critical temperature and field of the superconductor, with greater enhancement away from the graphene Dirac point. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000356129800012 |
Publication Date |
2015-06-15 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
2 |
Open Access |
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| |
Notes |
; This work was financially supported by the Engineering and Physical Sciences Research Council, and an NPL/EPSRC Joint Postdoctoral Partnership. Supporting data for this paper is available at the DSpace@Cambridge data repository (https://www.repository.cam.ac.uk/handle/1810/248242). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:126982 |
Serial |
3865 |
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| Permanent link to this record |
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| |
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Author |
Chaves, A.; Low, T.; Avouris, P.; Çakir, D.; Peeters, F.M. |
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| |
Title |
Anisotropic exciton Stark shift in black phosphorus |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
155311 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
We calculate the excitonic spectrum of few-layer black phosphorus by direct diagonalization of the effective mass Hamiltonian in the presence of an applied in-plane electric field. The strong attractive interaction between electrons and holes in this system allows one to investigate the Stark effect up to very high ionizing fields, including also the excited states. Our results show that the band anisotropy in black phosphorus becomes evident in the direction-dependent field-induced polarizability of the exciton. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
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Wos |
000353459200005 |
Publication Date |
2015-04-27 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1098-0121; 1550-235x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
88 |
Open Access |
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| |
Notes |
; Discussions with J. M. Pereira Jr. and J. S. de Souza are gratefully acknowledged. This work was supported by the Brazilian Council for Research (CNPq) through the PQ and Science Without Borders programs, the Flemish Science Foundation (FWO-Vl), the Methusalem programme of the Flemish government, and the Bilateral program (CNPq-FWO) between Flanders and Brazil. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:132506 |
Serial |
4141 |
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| Permanent link to this record |
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Author |
Sadeghi, A.; Neek-Amal, M.; Berdiyorov, G.R.; Peeters, F.M. |
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| |
Title |
Diffusion of fluorine on and between graphene layers |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
014304 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using first-principles calculations and reactive force field molecular dynamics simulations, we study the structural properties and dynamics of a fluorine (F) atom, either adsorbed on the surface of single layer graphene (F/GE) or between the layers of AB stacked bilayer graphene (F@ bilayer graphene). It is found that the diffusion of the F atom is very different in those cases, and that the mobility of the F atom increases by about an order of magnitude when inserted between two graphene layers. The obtained diffusion constant for F/GE is twice larger than that experimentally found for gold adatom and theoretically found for C-60 molecule on graphene. Our study provides important physical insights into the dynamics of fluorine atoms between and on graphene layers and explains the mechanism behind the separation of graphite layers due to intercalation of F atoms. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
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Wos |
000349125800002 |
Publication Date |
2015-01-08 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
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| |
ISSN |
1098-0121; 1550-235x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
15 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI) and the Methusalem Foundation of the Flemish Government. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:132561 |
Serial |
4161 |
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| Permanent link to this record |
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Author |
Pavlović, S.; Peeters, F.M. |
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| |
Title |
Electronic properties of triangular and hexagonal MoS2 quantum dots |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
155410 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using the tight-binding approach, we calculate the electronic structure of triangular and hexagonal MoS2 quantum dots. Due to the orbital asymmetry we show that it is possible to form quantum dots with the same shape but having different electronic properties. The electronic states of triangular and hexagonal quantum dots are explored, as well as the local and total density of states and the convergence towards the bulk spectrum with dot size is investigated. Our calculations show that: (1) edge states appear in the band gap, (2) that there are a larger number of electronic states in the conduction band as compared to the valence band, and (3) the relative number of edge states decreases with increasing dot size. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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| |
Language |
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Wos |
000352591200005 |
Publication Date |
2015-04-11 |
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| |
Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
1098-0121; 1550-235x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
44 |
Open Access |
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| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI) and the Methusalem Foundation of the Flemish government. Stefan Pavlovic is supported by JoinEU-SEE IV, Erasmus Mundus Action 2 programme. We thank J. M. Pereira for interesting discussions. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:132516 |
Serial |
4170 |
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| Permanent link to this record |
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Author |
Hannibal, S.; Kettmann, P.; Croitoru, M.D.; Vagov, A.; Axt, V.M.; Kuhn, T. |
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Title |
Quench dynamics of an ultracold Fermi gas in the BCS regime : spectral properties and confinement-induced breakdown of the Higgs mode |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : A : atomic, molecular and optical physics |
Abbreviated Journal |
Phys Rev A |
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Volume |
91 |
Issue |
91 |
Pages |
043630 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The Higgs amplitude mode of the order parameter of an ultracold confined Fermi gas in the BCS regime after a quench of the coupling constant is analyzed theoretically. A characteristic feature is a damped oscillation which at a certain transition time changes into a rather irregular dynamics. We compare the numerical solution of the full set of nonlinear equations of motion for the normal and anomalous Bogoliubov quasiparticle excitations with a linearized approximation. In doing so the transition time as well as the difference between resonant systems, i.e., systems where the Fermi energy is close to a sub-band minimum, and off-resonant systems can be well understood and traced back to the system and geometry parameters. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000353448500005 |
Publication Date |
2015-04-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
|
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| |
ISSN |
1094-1622; 1050-2947 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.925 |
Times cited |
10 |
Open Access |
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Notes |
; M.D.C. acknowledges support by the BELSPO Back to Belgium Grant. ; |
Approved |
Most recent IF: 2.925; 2015 IF: NA |
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| |
Call Number |
UA @ lucian @ c:irua:132509 |
Serial |
4235 |
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| Permanent link to this record |
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Author |
Michel, K.H.; Costamagna; Peeters, F.M. |
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Title |
Theory of anharmonic phonons in two-dimensional crystals |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
91 |
Issue |
91 |
Pages |
134302 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Anharmonic effects in an atomic monolayer thin crystal with honeycomb lattice structure are investigated by analytical and numerical lattice dynamical methods. Starting from a semiempirical model for anharmonic couplings of third and fourth orders, we study the in-plane and out-of-plane (flexural) mode components of the generalized wave vector dependent Gruneisen parameters, the thermal tension and the thermal expansion coefficients as a function of temperature and crystal size. From the resonances of the displacement-displacement correlation functions, we obtain the renormalization and decay rate of in-plane and flexural phonons as a function of temperature, wave vector, and crystal size in the classical and in the quantum regime. Quantitative results are presented for graphene. There, we find that the transition temperature T-alpha from negative to positive thermal expansion is lowered with smaller system size. Renormalization of the flexural mode has the opposite effect and leads to values of T-alpha approximate to 300 K for systems of macroscopic size. Extensive numerical analysis throughout the Brillouin zone explores various decay and scattering channels. The relative importance of normal and umklapp processes is investigated. The work is complementary to crystalline membrane theory and computational studies of anharmonic effects in two-dimensional crystals. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
Lancaster, Pa |
Editor |
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Language |
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Wos |
000353031000001 |
Publication Date |
2015-04-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1098-0121; 1550-235x |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
38 |
Open Access |
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| |
Notes |
; We thank B. Verberck, D. Lamoen, and A. Dobry for useful comments. We acknowledge funding from the FWO (Belgium)-MINCyT (Argentina) collaborative research project. This work is supported by the EuroGRAPHENE project CONGRAN. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
UA @ lucian @ c:irua:132512 |
Serial |
4263 |
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| Permanent link to this record |
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Author |
Tahir, M.; Vasilopoulos, P.; Peeters, F.M. |
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Title |
Magneto-optical transport properties of monolayer phosphorene |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
92 |
Issue |
92 |
Pages |
045420 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electronic properties of monolayer phosphorene are exotic due to its puckered structure and large intrinsic direct band gap. We derive and discuss its band structure in the presence of a perpendicular magnetic field. Further, we evaluate the magneto-optical Hall and longitudinal optical conductivities as functions of temperature, magnetic field, and Fermi energy, and show that they are strongly influenced by the magnetic field. The imaginary part of the former and the real part of the latter exhibit regular interband oscillations as functions of the frequency omega in the range (h) over bar omega similar to 1.5-2 eV. Strong intraband responses in the latter and weak ones in the former occur at much lower frequencies. The magneto-optical response can be tuned in the microwave-to-terahertz and visible frequency ranges in contrast with a conventional two-dimensional electron gas or graphene in which the response is limited to the terahertz regime. This ability to isolate carriers in an anisotropic structure may make phosphorene a promising candidate for new optical devices. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000358373600003 |
Publication Date |
2015-07-23 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
68 |
Open Access |
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| |
Notes |
; This work was supported by the the Canadian NSERC Grant No. OGP0121756 (M.T., P.V.) and by the Flemish Science Foundation (FWO-Vl) (F.M.P.). ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:127192 |
Serial |
1903 |
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| Permanent link to this record |
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Author |
Shakouri, K.; Peeters, F.M. |
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Title |
Spin- and pseudospin-polarized quantum Hall liquids in HgTe quantum wells |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
92 |
Issue |
92 |
Pages |
045416 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
A Hg(Cd)Te insulator heterostructure hosts a two-dimensional electron system that can simulate the physics of Dirac fermions with only a single valley. We investigate the magnetotransport properties of this structure and show that, unlike most two-dimensional crystals with spin and valley coupled levels, the Shubnikov-de Haas oscillations exhibit a high spin polarization in the absence of any valley degree of freedom. This effect can be observed using magnetospectroscopy measurements for quantum well thicknesses corresponding to either the topologically trivial or quantum spin Hall phases. The pseudospin texture of the electrons near the Fermi level is also studied and we show that a tunable pseudospin-polarized quantum Hall liquid can only be observed for thicknesses corresponding to the inverted regime. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000358032000002 |
Publication Date |
2015-07-17 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
3 |
Open Access |
|
|
| |
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government. ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:127097 |
Serial |
3077 |
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| Permanent link to this record |
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Author |
Shakouri, K.; Simchi, H.; Esmaeilzadeh, M.; Mazidabadi, H.; Peeters, F.M. |
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Title |
Tunable spin and charge transport in silicene nanoribbons |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
92 |
Issue |
92 |
Pages |
035413 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using the tight-binding formalism, we study spin and charge transport through a zigzag silicene ribbon subject to an external electric field E-z. The effect of an exchange field M-z is also taken into account and its consequences on the band structure as well as spin transport are evaluated. We show that the band structure lacks spin inversion symmetry in the presence of intrinsic spin-orbit interaction in combination of E-z and M-z fields. Our quantum transport calculations indicate that for certain energy ranges of the incoming electrons the silicene ribbon can act as a controllable high-efficiency spin polarizer. The polarization maxima occur simultaneously with the van Hove singularities of the local density of states. In this case, the combination of electric and exchange fields is the key to achieving nearly perfect spin polarization, which also leads to the appearance of additional narrow plateaus in the quantum conductance. Moreover, we demonstrate that the output current still remains completely spin-polarized for low-energy carriers even when a few edge vacancies are present. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000357806900004 |
Publication Date |
2015-07-10 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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| |
ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.836 |
Times cited |
70 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:127099 |
Serial |
3746 |
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| Permanent link to this record |
