| Records |
| Author |
de de Meux, A.J.; Pourtois, G.; Genoe, J.; Heremans, P. |
| Title |
Defects in amorphous semiconductors : the case of amorphous indium gallium zinc oxide |
Type |
A1 Journal article |
| Year |
2018 |
Publication  |
Physical review applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
9 |
Issue |
9 |
Pages |
054039 |
| Keywords |
A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT) |
| Abstract |
Based on a rational classification of defects in amorphous materials, we propose a simplified model to describe intrinsic defects and hydrogen impurities in amorphous indium gallium zinc oxide (a-IGZO). The proposed approach consists of organizing defects into two categories: point defects, generating structural anomalies such as metal-metal or oxygen-oxygen bonds, and defects emerging from changes in the material stoichiometry, such as vacancies and interstitial atoms. Based on first-principles simulations, it is argued that the defects originating from the second group always act as perfect donors or perfect acceptors. This classification simplifies and rationalizes the nature of defects in amorphous phases. In a-IGZO, the most important point defects are metal-metal bonds (or small metal clusters) and peroxides (O-O single bonds). Electrons are captured by metal-metal bonds and released by the formation of peroxides. The presence of hydrogen can lead to two additional types of defects: metal-hydrogen defects, acting as acceptors, and oxygen-hydrogen defects, acting as donors. The impact of these defects is linked to different instabilities observed in a-IGZO. Specifically, the diffusion of hydrogen and oxygen is connected to positive-and negative-bias stresses, while negative-bias illumination stress originates from the formation of peroxides. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
American Physical Society |
Place of Publication |
College Park, Md |
Editor |
|
| Language |
|
Wos |
000433070900003 |
Publication Date |
2018-05-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
7 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ lucian @ c:irua:151497 |
Serial |
5019 |
| Permanent link to this record |
| |
|
| |
| Author |
Torsello, D.; Ummarino, G.A.; Bekaert, J.; Gozzelino, L.; Gerbaldo, R.; Tanatar, M.A.; Canfield, P.C.; Prozorov, R.; Ghigo, G. |
| Title |
Tuning the intrinsic anisotropy with disorder in the CaKFE₄As₄ superconductor |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
13 |
Issue |
6 |
Pages |
064046-64049 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We report on the anisotropy of the London penetration depth of CaKFe4As4, discussing how it relates to its electronic structure and how it modifies under introduction of disorder, both chemically induced (by Ni substitution) and irradiation induced (by 3.5-MeV protons). Indeed, CaKFe4As4 is particularly suitable for the study of fundamental superconducting properties due to its stoichiometric composition, exhibiting clean-limit behavior in the pristine samples and having a fairly high critical temperature, T-c approximate to 35 K. The London penetration depth lambda(L) is measured with a microwave-coplanar-resonator technique that allows us to deconvolve the anisotropic contributions lambda(L,ab) and lambda(L,c) and obtain the anisotropy parameter gamma(lambda) = lambda(L,c)/lambda(L,ab). The gamma(lambda) (T) found for the undoped pristine sample is in good agreement with previous literature and is here compared to ab initio density-functional-theory and Eliashberg calculations. The dependence of gamma(lambda) (T) on both chemical and irradiation-induced disorder is discussed to highlight which method is more suitable to decrease the direction dependence of the electromagnetic properties while maintaining a high critical temperature. Lastly, the relevance of an intrinsic anisotropy such as gamma(lambda) on application-related anisotropic parameters (critical current, pinning) is discussed in light of the recent employment of CaKFe4As4 in the production of wires. |
| Address |
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| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000540915800003 |
Publication Date |
2020-06-19 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
4 |
Open Access |
|
| Notes |
; This work was partially supported by the Italian Ministry of Education, University and Research (Project PRIN “HIBiSCUS,” Grant No. 201785KWLE). J.B. acknowledges the support of a postdoctoral fellowship of the Research Foundation-Flanders (FWO). The computational resources and services used for the first-principles calculations in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. Work done at Ames Laboratory was supported by the U.S. Department of Energy, Office of Basic Energy Science, Division of Materials Sciences and Engineering. Ames Laboratory is operated for the U.S. Department of Energy by Iowa State University under Contract No. DE-AC02-07CH11358. G.A.U. acknowledges support from the MEPhI Academic Excellence Project (Contract No. 702.a03.21.0005). ; |
Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:170178 |
Serial |
6641 |
| Permanent link to this record |
| |
|
| |
| Author |
Yin, L.; Juneja, R.; Lindsay, L.; Pandey, T.; Parker, D.S. |
| Title |
Semihard iron-based permanent-magnet materials |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
15 |
Issue |
2 |
Pages |
024012 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Permanent magnets generally require a favorable, but difficult-to-achieve combination of high magnetization, Curie point, and magnetic anisotropy. Thus there have been few, if any, viable permanent magnets developed since the 1982 discovery of Nd2Fe14B [M. Sagawa, S. Fujimura, H. Yamamoto, Y. Matsuura, and S. Hirosawa, J. Appl. Phys. 57, 4094 (1985)]. Here we point out, both by direct first-principles calculations on the iron carbides and silicides Fe5C2, Fe5SiC, and Fe7C3 as well as a discussion of recent experimental findings, that there are numerous rare-earth-free iron-rich potential permanent-magnet materials with sufficient intrinsic magnetic properties to reasonably achieve room-temperature energy products of 20-25 MG Oe. This is substantially better than the performance of the best available rare-earth-free magnets based on ferrite, as well as shape-anisotropy-employing alnico. These magnets could plausibly fill, at low cost, the present performance “gap” [J. M. D. Coey, Scr. Mater. 67, 524 (2012)] between the best rare-earth-free magnets and rare-earth magnets such as Nd2Fe14B and Sm-Co. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000614707800002 |
Publication Date |
2021-02-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:176624 |
Serial |
6734 |
| Permanent link to this record |
| |
|
| |
| Author |
Sethu, K.K.V.; Ghosh, S.; Couet, S.; Swerts, J.; Sorée, B.; De Boeck, J.; Kar, G.S.; Garello, K. |
| Title |
Optimization of tungsten beta-phase window for spin-orbit-torque magnetic random-access memory |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
16 |
Issue |
6 |
Pages |
064009 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Switching induced by spin-orbit torque (SOT) is being vigorously explored, as it allows the control of magnetization using an in-plane current, which enables a three-terminal magnetic-tunnel-junction geometry with isolated read and write paths. This significantly improves the device endurance and the read stability, and allows reliable subnanosecond switching. Tungsten in the beta phase, beta-W, has the largest reported antidamping SOT charge-to-spin conversion ratio (theta(AD) approximate to -60%) for heavy metals. However, beta-W has a limitation when one is aiming for reliable technology integration: the beta phase is limited to a thickness of a few nanometers and enters the alpha phase above 4 nm in our samples when industry-relevant deposition tools are used. Here, we report our approach to extending the range of beta-W, while simultaneously improving the SOT efficiency by introducing N and O doping of W. Resistivity and XRD measurements confirm the extension of the beta phase from 4 nm to more than 10 nm, and transport characterization shows an effective SOT efficiency larger than -44.4% (reaching approximately -60% for the bulk contribution). In addition, we demonstrate the possibility of controlling and enhancing the perpendicular magnetic anisotropy of a storage layer (Co-Fe-B). Further, we integrate the optimized W(O, N) into SOT magnetic random-access memory (SOT-MRAM) devices and project that, for the same thickness of SOT material, the switching current decreases by 25% in optimized W(O, N) compared with our standard W. Our results open the path to using and further optimizing W for integration of SOT-MRAM technology. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
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| Language |
|
Wos |
000729005800002 |
Publication Date |
2021-12-03 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:184832 |
Serial |
7007 |
| Permanent link to this record |
| |
|
| |
| Author |
Tao, Z.H.; Dong, H.M.; Milošević, M.V.; Peeters, F.M.; Van Duppen, B. |
| Title |
Tailoring dirac plasmons via anisotropic dielectric environment by design |
Type |
A1 Journal article |
| Year |
2021 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
16 |
Issue |
5 |
Pages |
054030 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Dirac plasmons in a two-dimensional (2D) crystal are strongly affected by the dielectric properties of the environment, due to interaction of their electric field lines with the surrounding medium. Using graphene as a 2D reservoir of free carriers, one can engineer a material configuration that provides an anisotropic environment to the plasmons. In this work, we discuss the physical properties of Dirac plasmons in graphene surrounded by an arbitrary anisotropic dielectric and exemplify how h-BN-based heterostructures can be designed to bear the required anisotropic characteristics. We calculate how dielec-tric anisotropy impacts the spatial propagation of the plasmons and find that an anisotropy-induced plasmon mode emerges, together with a damping pathway, that stem from the out-of-plane off-diagonal elements in the dielectric tensor. Furthermore, we find that one can create hyperbolic plasmons by inher-iting the dielectric hyperbolicity of the designed material environment. Strong control over plasmon propagation patterns can be realized in a similar manner. Finally, we show that in this way one can also control the polarization of the light-matter excitations that constitute the plasmon. Taken together, our results promote the design of the dielectric environment as an effective path to tailor the plasmonic response of graphene on the nanoscopic level. |
| Address |
|
| Corporate Author |
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Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000720372500002 |
Publication Date |
2021-11-15 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.808 |
Times cited |
1 |
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:184063 |
Serial |
7028 |
| Permanent link to this record |
| |
|
| |
| Author |
Tiwari, S.; Van de Put, M.L.; Temst, K.; Vandenberghe, W.G.; Sorée, B. |
| Title |
Atomistic modeling of spin and electron dynamics in two-dimensional magnets switched by two-dimensional topological insulators |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
19 |
Issue |
1 |
Pages |
014040-14049 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
To design fast memory devices, we need material combinations that can facilitate fast read and write operations. We present a heterostructure comprising a two-dimensional (2D) magnet and a 2D topological insulator (TI) as a viable option for designing fast memory devices. We theoretically model the spin-charge dynamics between 2D magnets and 2D TIs. Using the adiabatic approximation, we combine the nonequi-librium Green's function method for spin-dependent electron transport and a time-quantified Monte Carlo method for simulating magnetization dynamics. We show that it is possible to switch a magnetic domain of a ferromagnet using the spin torque from spin-polarized edge states of a 2D TI. We show further that the switching of 2D magnets by TIs is strongly dependent on the interface exchange (Jint), and an opti-mal interface exchange, is required for efficient switching. Finally, we compare experimentally grown Cr compounds and show that Cr compounds with higher anisotropy (such as CrI3) result in a lower switching speed but a more stable magnetic order. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000920227500002 |
Publication Date |
2023-01-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:194312 |
Serial |
7283 |
| Permanent link to this record |
| |
|
| |
| Author |
Jiang, J.; Milošević, M.V.; Wang, Y.-L.; Xiao, Z.-L.; Peeters, F.M.; Chen, Q.-H. |
| Title |
Field-free superconducting diode in a magnetically nanostructured superconductor |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Physical review applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
18 |
Issue |
3 |
Pages |
034064-34069 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A strong superconducting diode effect (SDE) is revealed in a thin superconducting film periodically nanostructured with magnetic dots. The SDE is caused by the current-activated dissipation mitigated by vortex-antivortex pairs (VAPs), which periodically nucleate under the dots, move and annihilate in the superconductor-eventually driving the system to the high-resistive state. Inversing the polarity of the applied current destimulates the nucleation of VAPs, the system remains superconducting up to far larger currents, leading to the pronounced diodic response. Our dissipative Ginzburg-Landau simulations detail the involved processes, and provide reliable geometric and parametric ranges for the experimental realiza-tion of such a nonvolatile superconducting diode, which operates in the absence of any applied magnetic field while being fluxonic by design. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000870234200001 |
Publication Date |
2022-09-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
2 |
Open Access |
OpenAccess |
| Notes |
|
Approved |
Most recent IF: 4.6 |
| Call Number |
UA @ admin @ c:irua:191539 |
Serial |
7307 |
| Permanent link to this record |
| |
|
| |
| Author |
Karaaslan, Y.; Yapicioglu, H.; Sevik, C. |
| Title |
Assessment of Thermal Transport Properties of Group-III Nitrides: A Classical Molecular Dynamics Study with Transferable Tersoff-Type Interatomic Potentials |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review Applied |
Abbreviated Journal |
Phys Rev Appl |
| Volume |
13 |
Issue |
3 |
Pages |
034027 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
In this study, by means of classical molecular dynamics simulations, we investigate the thermal-transport properties of hexagonal single-layer, zinc-blend, and wurtzite phases of BN, AlN, and GaN crystals, which are very promising for the application and design of high-quality electronic devices. With this in mind, we generate fully transferable Tersoff-type empirical interatomic potential parameter sets by utilizing an optimization procedure based on particle-swarm optimization. The predicted thermal properties as well as the structural, mechanical, and vibrational properties of all materials are in very good agreement with existing experimental and first-principles data. The impact of isotopes on thermal transport is also investigated and between approximately 10 and 50% reduction in phonon thermal transport with random isotope distribution is observed in BN and GaN crystals. Our investigation distinctly shows that the generated parameter sets are fully transferable and very useful in exploring the thermal properties of systems containing these nitrides. |
| 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 |
|
Wos |
000518820200003 |
Publication Date |
2020-03-10 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.6; 2020 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:193766 |
Serial |
7508 |
| Permanent link to this record |
| |
|
| |
| Author |
Sevik, C.; Çakir, D. |
| Title |
Tailoring Storage Capacity and Ion Kinetics in Ti2CO2/Graphene Heterostructures by Functionalization of Graphene |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
12 |
Issue |
1 |
Pages |
014001 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using first-principles calculations, we evaluate the electrochemical performance of heterostructures made up of Ti2CO2 and chemically modified graphene for Li batteries. We find that heteroatom doping and molecule intercalation have a significant impact on the storage capacity and Li migration barrier energies. While N and S doping do not improve the storage capacity, B doping together with molecule interaction make it possible to intercalate two layers of Li, which stick separately to the surface of Ti2CO2 and B-doped graphene. The calculated diffusion-barrier energies (E-diff), which are between 0.3 and 0.4 eV depending on Li concentration, are quite promising for fast charge and discharge rates. Besides, the predicted E-diff as much as 2 eV for the diffusion of the Li atom from the Ti2CO2 surface to the B-doped graphene surface significantly suppresses the interlayer Li migration, which diminishes the charge and discharge rates. The calculated volume and lattice parameter changes indicate that Ti2CO2/graphene hybrid structures exhibit cyclic stability against Li loading and unloading. Consequently, first-principles calculations we perform evidently highlight the favorable effect of molecular intercalation on the capacity improvement of ion batteries. |
| 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 |
000473312000001 |
Publication Date |
2019-07-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:193755 |
Serial |
8640 |
| Permanent link to this record |
| |
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| |
| Author |
Foltyn, M.; Norowski, K.; Wyszynski, M.J.; De Arruda, A.S.; Milošević, M.V.; Zgirski, M. |
| Title |
Probing confined vortices with a superconducting nanobridge |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
19 |
Issue |
4 |
Pages |
044073-12 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We realize a superconducting nanodevice in which vortex traps in the form of an aluminum square are integrated with a Dayem nanobridge. We perform field cooling of the traps arriving to different vortex configurations, dependent on the applied magnetic field, to demonstrate that the switching current of the bridge is highly sensitive to the presence and location of vortices in the trap. Our measurements exhibit unprecedented precision and ability to detect the first and successive vortex entries into all fabricated traps, from few hundred nm to 2 mu m in size. The experimental results are corroborated by Ginzburg-Landau simulations, which reveal the subtle yet crucial changes in the density of the superconducting condensate in the vicinity of the bridge with every additional vortex entry and relocation inside the trap. An ease of integration and simplicity make our design a convenient platform for studying dynamics of vortices in strongly confining geometries, involving a promise to manipulate vortex states electronically with simultaneous in situ control and monitoring. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000980861100007 |
Publication Date |
2023-04-24 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
Not_Open_Access |
| Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:197356 |
Serial |
8918 |
| Permanent link to this record |
| |
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| |
| Author |
Akande, S.O.; Samanta, B.; Sevik, C.; Cakir, D. |
| Title |
First-principles investigation of mechanical and thermal properties of M Al B (M = Mo, W), Cr₂ AlB₂, and Ti₂ In B₂ |
Type |
A1 Journal article |
| Year |
2023 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
20 |
Issue |
4 |
Pages |
044064-17 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The atomically laminated layered ternary transition-metal borides (the MAB phases) have demonstrated outstanding properties and have been applied in various fields. Understanding their thermal and mechanical properties is critical to determining their applicability in various fields such as high-temperature applications. To achieve this, we conducted first-principles calculations based on density-functional theory and the quasiharmonic approximation to determine the thermal expansion coefficients, Gruneisen parameters, bulk moduli, hardness, thermal conductivity, electron-phonon coupling parameters, and the structural and vibrational properties of MoAlB, WAlB, Cr2AlB2, and Ti2InB2. We found varying degrees of anisotropy in the thermal expansion and mechanical properties in spite of similarities in their crystal structures. MoAlB has a mild degree of anisotropy in its thermal expansion coefficient (TEC), while Cr2AlB2 and WAlB display the highest level of TEC anisotropy. We assessed various empirical models to calculate hardness and thermal conductivity, and correlated the calculated values with the material properties such as elastic moduli, Gruneisen parameter, Debye temperature, and type of bonding. Owing to their higher Gruneisen parameters, implying a greater degree of anharmonicity in lattice vibrations and lower phonon group velocities, MoAlB and WAlB have significantly lower lattice thermal conductivity values than those of Cr2AlB2 and Ti2InB2. The hardness and lattice thermal conductivity of MAB phases can be predicted with high accuracy if one utilizes an appropriate model. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
001106456600003 |
Publication Date |
2023-10-25 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
| Impact Factor |
4.6 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 4.6; 2023 IF: 4.808 |
| Call Number |
UA @ admin @ c:irua:202078 |
Serial |
9037 |
| Permanent link to this record |
| |
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| |
| Author |
Vermeulen, B.B.; Monteiro, M.G.; Giuliano, D.; Sorée, B.; Couet, S.; Temst, K.; Nguyen, V.D. |
| Title |
Magnetization-switching dynamics driven by chiral coupling |
Type |
A1 Journal article |
| Year |
2024 |
Publication |
Physical review applied |
Abbreviated Journal |
|
| Volume |
21 |
Issue |
2 |
Pages |
024050-11 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The Dzyaloshinskii-Moriya interaction (DMI) is known to play a central role in stabilizing chiral spin textures such as skyrmions and domain walls (DWs). Electrical manipulation of DW and skyrmion motion offers possibilities for next-generation, scalable and energy-efficient spintronic devices. However, achieving the full potential of these nanoscale devices requires overcoming several challenges, including reliable electrical write and read techniques for these magnetic objects, and addressing pinning and Joule-heating concerns. Here, through micromagnetic simulations and analytical modeling, we show that DMI can directly induce magnetization switching of a nanomagnet with perpendicular magnetic anisotropy (PMA). We find that the switching is driven by the interplay between the DMI-induced magnetic frustration and the PMA. By introducing magnetic tunnel junctions to electrically access and control the magnetization direction of the PMA nanomagnet, we first show the potential of this concept to enable high-density fieldfree spin-orbit torque magnetic random-access memory. Ultimately, we demonstrate that it offers a way of transferring and processing spin information for logic operation without relying on current-driven DW or skyrmion motion. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
001187487900001 |
Publication Date |
2024-02-26 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2331-7019 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
|
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ admin @ c:irua:205518 |
Serial |
9157 |
| Permanent link to this record |
| |
|
| |
| Author |
Nogaret, A.; Lambert, N.J.; Peeters, F.M. |
| Title |
Electrically induced spin resonance fluorescence : 2 : fluorescence spectra |
Type |
A1 Journal article |
| Year |
2007 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
76 |
Issue |
7 |
Pages |
|
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We model the fluorescence spectra of planar spin oscillators to find conditions that maximize spin resonance fluorescence. Spin oscillators perform Rabi oscillations under the effect of a periodic effective magnetic field caused by the winding motion of an electron in a gradient of magnetic field. We show that, despite the weak coupling of the spin magnetic dipole to the vacuum, spin oscillators excited by a direct current output a few nanowatts of microwave power, which is comparable to the best microwave sources. The large quantum efficiency relies on the combination of two effects. On the one hand, the spontaneous emission rate is enhanced by the synchronization of spin oscillators, which interact through the microwave field that they emit. On the other hand, the huge Rabi frequencies experienced by spin oscillators promote spins into upper levels of Zeeman transitions, from which a radiative cascade is triggered. We demonstrate different regimes of fluorescence which correspond to different values of the Rabi period relative to the spontaneous decay time and to the oscillator dwell time in the gradient of magnetic field. We investigate the device parameters which make these regimes experimentally accessible and find conditions that optimize microwave output. We find that microwave emission is centered around the cutoff frequency of spin oscillators. This has the advantage that the peak emission frequency may be tuned from zero continuously up to a few hundred gigahertz using an electrostatic gate. Quite remarkably for a spintronics effect, electrically induced spin resonance fluorescence does not require the injection of a spin polarized current. In fact, we show that microwave spectra are mostly independent of the incoming spin polarization except for magnetic waveguides which are shorter than a certain critical length, which we will specify. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000249155300092 |
Publication Date |
2007-08-09 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
8 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2007 IF: 3.172 |
| Call Number |
UA @ lucian @ c:irua:66118 |
Serial |
898 |
| Permanent link to this record |
| |
|
| |
| Author |
Shi, J.M.; Koenraad, P.M.; van de Stadt, A.F.W.; Peeters, F.M.; Devreese, J.T.; Wolter, J.H. |
| Title |
Electronic structure of a Si \delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier |
Type |
A1 Journal article |
| Year |
1996 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
54 |
Issue |
11 |
Pages |
7996-8004 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
| Abstract |
We present a theoretical study of the electronic structure of a heavily Si delta-doped layer in a GaAs/AlxGa1-xAs/GaAs quantum barrier. In this class of structures the effect of DX centers on the electronic properties can be tuned by changing the AlxGa1-xAs barrier width and/or the Al concentration, which leads to a lowering of the DX level with respect to the Fermi energy without disturbing the wave functions much. A self-consistent approach is developed in which the effective confinement potential and the Fermi energy of the system, the energies, the wave functions, and the electron densities of the discrete subbands have been obtained as a function of both the material parameters of the samples and the experimental conditions. The effect of DX centers on such structures at nonzero temperature and under an external pressure is investigated for three different models: (1) the DX(nc)(0) model with no correlation effects, (2) the d(+)/DX(0) model, and (3) the d(+)/DX(-) model with inclusion of correlation effects. In the actual calculation, influences of the background accepters, the discontinuity of the effective mass of the electrons at the interfaces of the different materials, band nonparabolicity, and the exchange-correlation energy of the electrons have been taken into account. We have found that (1) introducing a quantum barrier into delta-doped GaAs makes it possible to control the energy gaps between different electronic; subbands; (2) the electron wave functions are mon spread out when the repellent effect of the barriers is increased as compared to those in delta-doped GaAs; (3) increasing the quantum-barrier height and/or the application of hydrostatic pressure are helpful to experimentally observe the effect of the DX centers through a decrease of the total free-electron density; and (4) the correlation effects of the charged impurities are important for the systems under study. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
A1996VL14500066 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
11 |
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ lucian @ c:irua:104388 |
Serial |
1012 |
| Permanent link to this record |
| |
|
| |
| Author |
Lamoen, D.; Ballone, P.; Parrinello, M. |
| Title |
Electronic structure, screening and charging effects at a metal/organic tunneling junction: a first principles study |
Type |
A1 Journal article |
| Year |
1996 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
54 |
Issue |
|
Pages |
5097 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
A1996VE48800102 |
Publication Date |
0000-00-00 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121; 0163-1829 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
33 |
Open Access |
|
| Notes |
|
Approved |
PHYSICS, CONDENSED MATTER 16/67 Q1 # |
| Call Number |
UA @ lucian @ c:irua:15820 |
Serial |
1018 |
| Permanent link to this record |
| |
|
| |
| Author |
Rosenauer, A.; Schowalter, M.; Glas, F.; Lamoen, D. |
| Title |
First-principles calculations of 002 structure factors for electron scattering in strained InxGa1-xAs |
Type |
A1 Journal article |
| Year |
2005 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
72 |
Issue |
8 |
Pages |
1-10 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
This work provides values of electron scattering 002 structure factors for InxGa1-xAs as a function of the In concentration x=0 to 1. These results allow accurate compositional analysis of pseudomorphically grown InxGa1-xAs/GaAs layers by transmission electron microscopy methods relying on the chemical sensitivity of the (002) beam. The calculations go beyond the limits of the isolated atom approximation, because they take into account charge redistribution effects between atomic sites in the crystal, strain, and static atomic displacements. The computations were performed by the full potential linearized augmented plane-wave method using a generalized gradient approximation for the exchange and correlation part of the potential. The calculations of strained InxGa1-xAs correspond to the strain state in specimens with large, small, and intermediate thickness in the electron beam direction. Additionally, the effect of static atomic displacements is taken into account. All results are listed in a parameterized form. The calculated 002 structure factor vanishes at an In concentration of 16.4%. This value is in a good agreement with previously reported experimental measurements. Hence, our results are a significant improvement with respect to the isolated atom approximation which is conventionally applied in transmission electron microscopy simulations, and which predicts a value of 22.5%. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000231564600106 |
Publication Date |
2005-08-12 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
42 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2005 IF: 3.185 |
| Call Number |
UA @ lucian @ c:irua:54918 |
Serial |
1201 |
| Permanent link to this record |
| |
|
| |
| Author |
Shields, P.A.; Nicholas, R.J.; Peeters, F.M.; Beaumont, B.; Gibart, P. |
| Title |
Free-carrier effects in gallium nitride epilayers: Valence-band dispersion |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
64 |
Issue |
8 |
Pages |
155303 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The dispersion of the A-valence-band in GaN has been deduced from the observation of high-index magnetoexcitonic states in polarized interband magnetoreflectivity and is found to be strongly nonparabolic with a mass in the range 1.2-1.8m(e). It matches the theory of Kim et al. [Phys. Rev. B 56, 7363 (1997)] extremely well, which also gives a strong k-dependent A-valence-band mass. A strong phonon coupling leads to quenching of the observed transitions at about an LO-phonon energy above the band gap and a strong nonparabolicity. The valence band was deduced from subtracting from the reduced dispersion the electron contribution with a model that includes a full treatment of the electron-phonon interaction. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000170623000005 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
13 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2001 IF: NA |
| Call Number |
UA @ lucian @ c:irua:37288 |
Serial |
1274 |
| Permanent link to this record |
| |
|
| |
| Author |
Leys, F.E.; March, N.H.; Lamoen, D. |
| Title |
High pressure limiting forms of the zero-temperature equations of state of Ta and Pu from relativistic Thomas-Fermi theory |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
67 |
Issue |
|
Pages |
064109 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000181501100021 |
Publication Date |
2003-03-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
1 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2003 IF: NA |
| Call Number |
UA @ lucian @ c:irua:45628 |
Serial |
1439 |
| Permanent link to this record |
| |
|
| |
| Author |
Stosic, D.; Mulkers, J.; Van Waeyenberge, B.; Ludermir, T.B.; Milošević, M.V. |
| Title |
Paths to collapse for isolated skyrmions in few-monolayer ferromagnetic films |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
95 |
Issue |
21 |
Pages |
214418 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Magnetic skyrmions are topological spin configurations in materials with chiral Dzyaloshinskii-Moriya interaction (DMI), that are potentially useful for storing or processing information. To date, DMI has been found in few bulk materials, but can also be induced in atomically thin magnetic films in contact with surfaces with large spin-orbit interactions. Recent experiments have reported that isolated magnetic skyrmions can be stabilized even near room temperature in few-atom-thick magnetic layers sandwiched between materials that provide asymmetric spin-orbit coupling. Here we present the minimum-energy path analysis of three distinct mechanisms for the skyrmion collapse, based on ab initio input and the performed atomic-spin simulations. We focus on the stability of a skyrmion in three atomic layers of Co, either epitaxial on the Pt(111) surface or within a hybrid multilayer where DMI nontrivially varies per monolayer due to competition between different symmetry breaking from two sides of the Co film. In laterally finite systems, their constrained geometry causes poor thermal stability of the skyrmion toward collapse at the boundary, which we show to be resolved by designing the high-DMI structure within an extended film with lower or no DMI. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Wos |
000404015500001 |
Publication Date |
2017-06-23 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
48 |
Open Access |
|
| Notes |
This work was supported by the Research Foundation, Flanders (FWO-Vlaanderen) and Brazilian agency CNPq (Grants No. 442668/2014-7 and No. 140840/2016-8). |
Approved |
Most recent IF: 3.836 |
| Call Number |
CMT @ cmt @c:irua:144865 |
Serial |
4704 |
| Permanent link to this record |
| |
|
| |
| Author |
Nicholas, R.J.; Sasaki, S.; Miura, N.; Peeters, F.M.; Shi, J.M.; Hai, G.Q.; Devreese, J.T.; Lawless, M.J.; Ashenford, D.E.; Lunn, B. |
| Title |
Interband magnetooptical studies of resonant polaron coupling in CdTe/Cd1-xMnxTe quantum-wells |
Type |
A1 Journal article |
| Year |
1994 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
50 |
Issue |
11 |
Pages |
7596-7601 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT); Theory of quantum systems and complex systems |
| Abstract |
Magnetoreflectivity measurements of the 1s and 2s exciton energies in a CdTe/Cd1-xMnxTe superlattice have been made in magnetic fields up to 45 T, showing the resonant polaron coupling of electrons to LO phonons. Strong reflectivity features are seen for both the 1s and 2s excitons, which show a strong field-dependent spin splitting due to the dilute magnetic barriers. At B-z=0, the 2s exciton feature is observed lying 18 meV above the Is state, and is shifted upward in energy by the magnetic fields. No resonant behavior occurs when the 2s state passes through the LO-phonon energy of 21 meV, but at higher fields of around 20 T, the resonances for both spin states (sigma(+/-)) of the 2s exciton broaden and show a strong anticrossing behavior. These experiments are shown to be in excellent agreement with a theoretical treatment which includes the resonant polaron coupling of the electrons alone. Both experiment and theory demonstrate an extremely strong resonant splitting of the 2s exciton states of approximately 11 meV, which is over 50% of the LO-phonon energy. The dominance of single-particle polaron coupling is attributed to the relative sizes of the polaron (35 Angstrom A) and the exciton (50 Angstrom A) radius. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
A1994PJ43700045 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.736 |
Times cited |
10 |
Open Access |
|
| Notes |
|
Approved |
no |
| Call Number |
UA @ lucian @ c:irua:99837 |
Serial |
1687 |
| Permanent link to this record |
| |
|
| |
| Author |
Singh, S.K.; Neek-Amal, M.; Costamagna, S.; Peeters, F.M. |
| 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 |
| Volume |
91 |
Issue |
91 |
Pages |
014101 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| 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. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000347921300001 |
Publication Date |
2015-01-05 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
40 |
Open Access |
|
| 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 |
| Call Number |
c:irua:123834 |
Serial |
2909 |
| Permanent link to this record |
| |
|
| |
| Author |
Leys, F.E.; March, N.H.; Angilella, G.G.N.; Lamoen, D. |
| Title |
Self consistent nonlocal linear-response theory of a relativistic electron gas |
Type |
A1 Journal article |
| Year |
2003 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
67 |
Issue |
|
Pages |
113105 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000182035100005 |
Publication Date |
2003-04-01 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; |
| Impact Factor |
3.836 |
Times cited |
|
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2003 IF: NA |
| Call Number |
UA @ lucian @ c:irua:45627 |
Serial |
2973 |
| Permanent link to this record |
| |
|
| |
| Author |
Misko, V.R.; Fomin, V.M.; Devreese, J.T. |
| Title |
Strong enhancement of superconductivity in a nanosized Pb bridge |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
64 |
Issue |
|
Pages |
014517,1-13 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
|
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
Lancaster, Pa |
Editor |
|
| Language |
|
Wos |
000169711900093 |
Publication Date |
2002-07-27 |
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
28 |
Open Access |
|
| Notes |
|
Approved |
Most recent IF: 3.836; 2001 IF: NA |
| Call Number |
UA @ lucian @ c:irua:34316 |
Serial |
3181 |
| Permanent link to this record |
| |
|
| |
| Author |
Wang, Y.J.; Leem, Y.A.; McCombe, B.D.; Wu, X.G.; Peeters, F.M.; Jones, E.D.; Reno, J.R.; Lee, X.Y.; Jiang, H.W. |
| Title |
Strong three-level resonant magnetopolaron effect due to the intersubband coupling in heavily modulation-doped GaAs/AlxGa1-xAs single quantum wells at high magnetic-fields |
Type |
A1 Journal article |
| Year |
2001 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
64 |
Issue |
16 |
Pages |
161303 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Electron cyclotron resonance CR) measurements have been carried out in magnetic fields up to 32 T to study electron-phonon interaction in two heavily modulation-delta -doped GaAs/Al0.3Ga0.7As single-quantum-well samples. No measurable resonant magnetopolaron effects were observed in either sample in the region of the GaAs longitudinal optical (LO) phonons. However, when the CR frequency is above LO phonon frequency, omega (LO)=E-LO/(h) over bar, at high magnetic fields (B>27 T), electron CR exhibits a strong avoided-level-crossing splitting for both samples at frequencies close to (omega (LO)+ (E-2-E-1)1 (h) over bar, where E-2, and E-1 are the energies of the bottoms of the second and the first subbands, respectively. The energy separation between the two branches is large with the minimum separation of 40 cm(-1) occurring at around 30.5 T. A detailed theoretical analysis, which includes a self-consistent calculation of the band structure and the effects of electron-phonon interaction on the CR, shows that this type of splitting is due to a three-level resonance between the second Landau level of the first electron subband and the lowest Landau level of the second subband plus one GaAs LO phonon. The absence of occupation effects in the final states and weak screening or this three-level process yields large energy separation even in the presence of high electron densities. Excellent agreement between the theory and the experimental results is obtained. |
| Address |
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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 |
000171866400009 |
Publication Date |
2002-07-27 |
| 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 |
0163-1829;1095-3795; |
ISBN |
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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 |
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Approved |
Most recent IF: 3.836; 2001 IF: NA |
| Call Number |
UA @ lucian @ c:irua:37278 |
Serial |
3184 |
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| Author |
Fomin, V.M.; Misko, V.R.; Devreese, J.T.; Moshchalkov, V.V. |
| Title |
Superconducting mesoscopic square loop |
Type |
A1 Journal article |
| Year |
1998 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
58 |
Issue |
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Pages |
11703-11715 |
| Keywords |
A1 Journal article; Electron Microscopy for Materials Science (EMAT); |
| Abstract |
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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 |
000076716700093 |
Publication Date |
2002-07-27 |
| 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 |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
43 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 3.836; 1998 IF: NA |
| Call Number |
UA @ lucian @ c:irua:21906 |
Serial |
3354 |
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| Author |
Verberck, B.; Nikolaev, A.V.; Michel, K.H. |
| Title |
Theoretical model for the structural phase transition at the metal-insulator transition in polymerized KC60 |
Type |
A1 Journal article |
| Year |
2002 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
66 |
Issue |
16 |
Pages |
165425-165425,14 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The recently discovered structural transition in polymerized KC60 at about 50 K results in a doubling of the unit cell volume and accompanies the metal-insulator transition. Here we show that the ((a) over right arrow+(c) over right arrow,(b) over right arrow,(a) over right arrow-(c) over right arrow) superstructure results from small orientational charge density waves along the polymer chains and concomitant displacements of the surrounding K+ ions. The effect is specific for the space group Pmnn of KC60 and is absent in RbC60 and CsC60 (space group I2/m). The mechanism is relevant for the metal-insulator transition. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000179286400135 |
Publication Date |
2002-10-30 |
| 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 |
0163-1829;1095-3795; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
10 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 3.836; 2002 IF: NA |
| Call Number |
UA @ lucian @ c:irua:94907 |
Serial |
3608 |
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| Author |
Callewaert, V.; Saniz, R.; Barbiellini, B.; Bansil, A.; Partoens, B. |
| Title |
Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
96 |
Issue |
8 |
Pages |
085135 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-)local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000408342600003 |
Publication Date |
2017-08-24 |
| 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 |
2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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| Notes |
Fonds Wetenschappelijk Onderzoek, G. 0224.14N ; U.S. Department of Energy, DE-FG02-07ER46352 DE-AC02-05CH11231 DE-SC0012575 ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
CMT @ cmt @c:irua:145703 |
Serial |
4703 |
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| Author |
da Costa, D.R.; Zarenia, M.; Chaves, A.; Farias, G.A.; Peeters, F.M. |
| Title |
Magnetic field dependence of energy levels in biased bilayer graphene quantum dots |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
93 |
Issue |
93 |
Pages |
085401 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Using the tight-binding approach, we study the influence of a perpendicular magnetic field on the energy levels of hexagonal, triangular, and circular bilayer graphene (BLG) quantum dots (QDs) with zigzag and armchair edges. We obtain the energy levels for AB (Bernal)-stacked BLG QDs in both the absence and the presence of a perpendicular electric field (i.e., biased BLG QDs). We find different regions in the spectrum of biased QDs with respect to the crossing point between the lowest-electron and -hole Landau levels of a biased BLG sheet. Those different regions correspond to electron states that are localized at the center, edge, or corner of the BLG QD. Quantum Hall corner states are found to be absent in circular BLG QDs. The spatial symmetry of the carrier density distribution is related to the symmetry of the confinement potential, the position of zigzag edges, and the presence or absence of interlayer inversion symmetry. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000369402400008 |
Publication Date |
2016-02-01 |
| 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 |
2469-9950 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
22 |
Open Access |
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| Notes |
; This work was financially supported by CNPq, under Contract No. NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES Foundation under the Process No. BEX 7178/13-1, the Flemish Science Foundation (FWO-Vl), the Bilateral programme between CNPq and FWO-Vl, and the Brazilian Program Science Without Borders (CsF). ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
c:irua:131623 |
Serial |
4038 |
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| Author |
Covaci, L.; Marsiglio, F. |
| Title |
Proximity effect and Josephson current in clean strong/weak/strong superconducting trilayers |
Type |
A1 Journal article |
| Year |
2006 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
73 |
Issue |
1 |
Pages |
014503 |
| Keywords |
A1 Journal article |
| Abstract |
Recent measurements of the Josephson critical current through LSCO/LCO/LSCO thin films showed an unusually large proximity effect. Using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian we describe the proximity effect in weak links between a superconductor with critical temperature T-c and one with critical temperature T-c('), where T-c > T-c('). The weak link (N-') is therefore a superconductor above its own critical temperature and the superconducting regions are considered to have either s-wave or d-wave symmetry. We note that the proximity effect is enhanced due to the presence of superconducting correlations in the weak link. The dc Josephson current is calculated, and we obtain a nonzero value for temperatures greater than T-c(') for sizes of the weak links that can be almost an order of magnitude greater than the conventional coherence length. Considering pockets of superconductivity in the N-' layer, we show that this can lead to an even larger effect on the Josephson critical current by effectively shortening the weak link. |
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Thesis |
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Place of Publication |
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Wos |
000235009000103 |
Publication Date |
2006-01-03 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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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 |
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| Impact Factor |
3.836 |
Times cited |
31 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 3.836; 2006 IF: 3.107 |
| Call Number |
UA @ lucian @ |
Serial |
4427 |
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| Author |
Bacaksiz, C.; Cahangirov, S.; Rubio, A.; Senger, R.T.; Peeters, F.M.; Sahin, H. |
| Title |
Bilayer SnS2 : tunable stacking sequence by charging and loading pressure |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
93 |
Issue |
93 |
Pages |
125403 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Employing density functional theory-based methods, we investigate monolayer and bilayer structures of hexagonal SnS2, which is a recently synthesized monolayer metal dichalcogenide. Comparison of the 1H and 1T phases of monolayer SnS2 confirms the ground state to be the 1T phase. In its bilayer structure we examine different stacking configurations of the two layers. It is found that the interlayer coupling in bilayer SnS2 is weaker than that of typical transition-metal dichalcogenides so that alternative stacking orders have similar structural parameters and they are separated with low energy barriers. A possible signature of the stacking order in the SnS2 bilayer has been sought in the calculated absorbance and reflectivity spectra. We also study the effects of the external electric field, charging, and loading pressure on the characteristic properties of bilayer SnS2. It is found that (i) the electric field increases the coupling between the layers at its preferred stacking order, so the barrier height increases, (ii) the bang gap value can be tuned by the external E field and under sufficient E field, the bilayer SnS2 can become a semimetal, (iii) the most favorable stacking order can be switched by charging, and (iv) a loading pressure exceeding 3 GPa changes the stacking order. The E-field tunable band gap and easily tunable stacking sequence of SnS2 layers make this 2D crystal structure a good candidate for field effect transistor and nanoscale lubricant applications. |
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Thesis |
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Place of Publication |
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Editor |
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| Language |
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Wos |
000371405000005 |
Publication Date |
2016-03-03 |
| 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 |
2469-9950;2469-9969; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
38 |
Open Access |
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| Notes |
; The calculations were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). C.B., H.S., and R.T.S. acknowledge support from TUBITAK Project No. 114F397. H.S. is supported by an FWO Pegasus Marie Curie Fellowship. S.C. and A.R. acknowledge financial support from the Marie Curie grant FP7-PEOPLE-2013-IEF Project No. 628876, the European Research Council (ERC-2010-AdG-267374), and Spanish grant Grupos Consolidados (IT578-13). S.C. acknowledges support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 115F388. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:132345 |
Serial |
4144 |
| Permanent link to this record |
