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Author |
Chen, Y.; Shanenko, A.A.; Peeters, F.M. |
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Title |
Vortex anomaly in low-dimensional fermionic condensates : quantum confinement breaks chirality |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
89 |
Issue |
5 |
Pages |
054513-54515 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Chiral fermions are responsible for low-temperature properties of vortices in fermionic condensates, both superconducting (charged) and superfluid (neutral). One of the most striking consequences of this fact is that the core of a single-quantum vortex collapses at low temperatures, T -> 0 (i.e., the Kramer-Pesch effect for superconductors), due to the presence of chiral quasiparticles in the vortex-core region. We show that the situation changes drastically for fermionic condensates confined in quasi-one-dimensional and quasi-two-dimensional geometries. Here quantum confinement breaks the chirality of in-core fermions. As a result, instead of the ultimate shrinking, the core of a single-quantum vortex extends at low temperatures, and the condensate profile surprisingly mimics the multiquantum vortex behavior. Our findings are relevant for nanoscale superconductors, such as recent metallic nanoislands on silicon, and also for ultracold superfluid Fermi gases in cigar-shaped and pancake-shaped atomic traps. |
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Wos |
000332396800005 |
Publication Date |
2014-02-19 |
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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 |
5 |
Open Access |
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Notes |
; This work was supported by the “Odysseus” Program of the Flemish Government, the Flemish Science Foundation (FWO-Vl), the Methusalem Program, and the National Science Foundation of China under Grant No. NSFC-11304134. A. A. S. acknowledges the support of Brazilian agencies CNPq and FACEPE (Grant No. APQ-0589-1.05/08). ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:115822 |
Serial |
3850 |
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Permanent link to this record |
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Author |
Dixit, H.; Lamoen, D.; Partoens, B. |
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Title |
Quasiparticle band structure of rocksalt-CdO determined using maximally localized Wannier functions |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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Volume |
25 |
Issue |
3 |
Pages |
035501-35505 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
CdO in the rocksalt structure is an indirect band gap semiconductor. Thus, in order to determine its band gap one needs to calculate the complete band structure. However, in practice, the exact evaluation of the quasiparticle band structure for the large number of k-points which constitute the different symmetry lines in the Brillouin zone can be an extremely demanding task compared to the standard density functional theory (DFT) calculation. In this paper we report the full quasiparticle band structure of CdO using a plane-wave pseudopotential approach. In order to reduce the computational effort and time, we make use of maximally localized Wannier functions (MLWFs). The MLWFs offer a highly accurate method for interpolation of the DFT or GW band structure from a coarse k-point mesh in the irreducible Brillouin zone, resulting in a much reduced computational effort. The present paper discusses the technical details of the scheme along with the results obtained for the quasiparticle band gap and the electron effective mass. |
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Place of Publication |
London |
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Wos |
000313100500010 |
Publication Date |
2012-12-12 |
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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 |
0953-8984;1361-648X; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.649 |
Times cited |
7 |
Open Access |
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Notes |
Fwo |
Approved |
Most recent IF: 2.649; 2013 IF: 2.223 |
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Call Number |
UA @ lucian @ c:irua:105296 |
Serial |
2801 |
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Permanent link to this record |
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Author |
Stankovski, M.; Antonius, G.; Waroquiers, D.; Miglio, A.; Dixit, H.; Sankaran, K.; Giantomassi, M.; Gonze, X.; Côté, M.; Rignanese, G.-M. |
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Title |
G0W0 band gap of ZnO : effects of plasmon-pole models |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
84 |
Issue |
24 |
Pages |
241201-241201,5 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Carefully converged calculations are performed for the band gap of ZnO within many-body perturbation theory (G0W0 approximation). The results obtained using four different well-established plasmon-pole models are compared with those of explicit calculations without such models (the contour-deformation approach). This comparison shows that, surprisingly, plasmon-pole models depending on the f-sum rule gives less precise results. In particular, it confirms that the band gap of ZnO is underestimated in the G0W0 approach as compared to experiment, contrary to the recent claim of Shih et al. [ Phys. Rev. Lett. 105 146401 (2010)]. |
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Wos |
000297766600001 |
Publication Date |
2011-12-06 |
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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 |
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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 |
81 |
Open Access |
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Notes |
; The authors would like to thank P. Zhang, S. Louie, J. Deslippe, P. Rinke, H. Jiang, C. Friedrich, and F. Bruneval for many helpful discussions. We are also very grateful to Y. Pouillon, A. Jacques, and J.-M. Beuken for their technical aid and expertise. M.C. and G.A. would like to acknowledge the support of NSERC and FQRNT. This work was supported by the Interuniversity Attraction Poles program (P6/42)-Belgian State-Belgian Science Policy, the Flemish Science Foundation (FWO-Vl) ISIMADE project, the EU's 7th Framework programme through the ETSF I3 e-Infrastructure project (Grant Agreement No. 211956), the Communaute francaise de Belgique, through the Action de Recherche Concertee 07/ 12-003 “Nanosystemes hybrides metal-organiques”, and the FNRS through FRFC Project No. 2.4.589.09.F. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:93963 |
Serial |
3533 |
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Permanent link to this record |
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Author |
Çakir, D.; Otalvaro, D.M.; Brocks, G. |
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Title |
Magnetoresistance in multilayer fullerene spin valves: A first-principles study |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
24 |
Pages |
245404 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Carbon-based molecular semiconductors are explored for application in spintronics because their small spinorbit coupling promises long spin lifetimes. We calculate the electronic transport from first principles through spin valves comprising bi-and tri-layers of the fullerene molecules C-60 and C-70, sandwiched between two Fe electrodes. The spin polarization of the current, and the magnetoresistance depend sensitively on the interactions at the interfaces between the molecules and the metal surfaces. They are much less affected by the thickness of the molecular layers. A high current polarization (CP > 90%) and magnetoresistance (MR > 100%) at small bias can be attained using C-70 layers. In contrast, the current polarization and the magnetoresistance at small bias are vanishingly small for C-60 layers. Exploiting a generalized Julliere model we can trace the differences in spin-dependent transport between C-60 and C-70 layers to differences between the molecule-metal interface states. These states also allow one to interpret the current polarization and the magnetoresistance as a function of the applied bias voltage. |
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Wos |
000345875200005 |
Publication Date |
2014-12-02 |
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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 |
13 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122177 |
Serial |
1928 |
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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 |
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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 |
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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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 |
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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 |
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 |
Bousige, C.; Rols, S.; Paineau, E.; Rouziere, S.; Mocuta, C.; Verberck, B.; Wright, J.P.; Kataura, H.; Launois, P. |
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Title |
Progressive melting in confined one-dimensional C60 chains |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
86 |
Issue |
4 |
Pages |
045446 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
C-60 fullerenes confined inside single-walled carbon nanotubes form an archetypal one-dimensional system. X-ray diffraction experiments, from room temperature to 1073 K, reveal an increasing melting phenomenon. Detailed analysis of the sawtooth peak characteristic of the fullerene organization allows the quantitative determination of fluctuations in intermolecular distances. The present results validate the predictions of one-dimensional statistical models. |
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Place of Publication |
Lancaster, Pa |
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Language |
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Wos |
000306925300007 |
Publication Date |
2012-08-01 |
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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 |
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Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:100835 |
Serial |
2726 |
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Permanent link to this record |
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Author |
Prodi, A.; Daoud-Aladine, A.; Gozzo, F.; Schmitt, B.; Lebedev, O.; Van Tendeloo, G.; Gilioli, E.; Bolzoni, F.; Aruga-Katori, H.; Takagi, H.; Marezio, M.; Gauzzi, A.; |
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Title |
Commensurate structural modulation in the charge- and orbitally ordered phase of the quadruple perovskite (NaMn3)Mn4O12 |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
90 |
Issue |
18 |
Pages |
180101 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
By means of synchrotron x-ray and electron diffraction, we studied the structural changes at the charge order transition T-CO = 176 K in the mixed-valence quadruple perovskite (NaMn3)Mn4O12. Below T-CO we find satellite peaks indicating a commensurate structural modulation with the same propagation vector q = ( 1/2,0,-1/2) of the CE magnetic structure that orders at low temperatures, similarly to the case of simple perovskites such as La0.5Ca0.5MnO3. In the present case, the modulated structure, together with the observation of a large entropy change at T-CO, gives evidence of a rare case of full Mn3+/Mn4+ charge and orbital order, consistent with the Goodenough-Kanamori model. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000344915100001 |
Publication Date |
2014-11-10 |
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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 |
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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 |
11 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:122097 |
Serial |
406 |
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Permanent link to this record |
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Author |
Li, B.; Peeters, F.M. |
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Title |
Tunable optical Aharonov-Bohm effect in a semiconductor quantum ring |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
83 |
Issue |
11 |
Pages |
115448-115448,13 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
By applying an electric field perpendicular to a semiconductor quantum ring we show that it is possible to modify the single particle wave function between quantum dot (QD)-like and ring-like. The constraints on the geometrical parameters of the quantum ring to realize such a transition are derived. With such a perpendicular electric field we are able to tune the Aharanov-Bohm (AB) effect for both the single particle and for excitons. The tunability is in both the strength of the AB effect as well as in its periodicity. We also investigate the strain induce potential inside the self-assembled quantum ring and the effect of the strain on the AB effect. |
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Corporate Author |
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Place of Publication |
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Language |
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Wos |
000288855200012 |
Publication Date |
2011-03-28 |
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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 |
25 |
Open Access |
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Notes |
; This work was supported by the EU-NoE: SANDiE, the Flemish Science Foundation (FWO-Vl), the Interuniversity Attraction Poles, Belgium State, Belgium Science Policy, and IMEC, vzw collaborative project. We are grateful to Prof. M. Tadic and Dr. Fei Ding for stimulating discussions. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:89376 |
Serial |
3744 |
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Permanent link to this record |
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Author |
Zhang, L.-F.; Covaci, L.; Milošević, M.V.; Berdiyorov, G.R.; Peeters, F.M. |
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Title |
Vortex states in nanoscale superconducting squares : the influence of quantum confinement |
Type |
A1 Journal article |
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Year |
2013 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
88 |
Issue |
14 |
Pages |
144501 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Bogoliubov-de Gennes theory is used to investigate the effect of the size of a superconducting square on the vortex states in the quantum confinement regime. When the superconducting coherence length is comparable to the Fermi wavelength, the shape resonances of the superconducting order parameter have strong influence on the vortex configuration. Several unconventional vortex states, including asymmetric ones, giant-multivortex combinations, and states comprising giant antivortices, were found as ground states and their stability was found to be very sensitive on the value of k(F)xi(0), the size of the sample W, and the magnetic flux Phi. By increasing the temperature and/or enlarging the size of the sample, quantum confinement is suppressed and the conventional mesoscopic vortex states as predicted by the Ginzburg-Laudau (GL) theory are recovered. However, contrary to the GL results we found that the states containing symmetry-induced vortex-antivortex pairs are stable over the whole temperature range. It turns out that the inhomogeneous order parameter induced by quantum confinement favors vortex-antivortex molecules, as well as giant vortices with a rich structure in the vortex core-unattainable in the GL domain. |
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Place of Publication |
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Language |
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Wos |
000325498300004 |
Publication Date |
2013-10-09 |
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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 |
19 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vlaanderen) and Methusalem Funding of the Flemish government. ; |
Approved |
Most recent IF: 3.836; 2013 IF: 3.664 |
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Call Number |
UA @ lucian @ c:irua:111145 |
Serial |
3891 |
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Permanent link to this record |
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Author |
Abdullah, H.M.; Bahlouli, H.; Peeters, F.M.; Van Duppen, B. |
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Title |
Confined states in graphene quantum blisters |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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Volume |
30 |
Issue |
38 |
Pages |
385301 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Bilayer graphene samples may exhibit regions where the two layers are locally delaminated forming a so-called quanttun blister in the graphene sheet. Electron and hole states can be confined in this graphene quantum blisters (GQB) by applying a global electrostatic bias. We scrutinize the electronic properties of these confined states under the variation of interlayer bias, coupling, and blister's size. The spectra display strong anti-crossings due to the coupling of the confined states on upper and lower layers inside the blister. These spectra are layer localized where the respective confined states reside on either layer or equally distributed. For finite angular momentum, this layer localization can be at the edge of the blister and corresponds to degenerate modes of opposite momenta. Furthermore, the energy levels in GQB exhibit electron-hole symmetry that is sensitive to the electrostatic bias. Finally, we demonstrate that confinement in GQB persists even in the presence of a variation in the interlayer coupling. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
London |
Editor |
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Language |
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Wos |
000443135000001 |
Publication Date |
2018-08-13 |
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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 |
0953-8984 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.649 |
Times cited |
6 |
Open Access |
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Notes |
; HMA and HB acknowledge the Saudi Center for Theoretical Physics (SCTP) for their generous support and the support of KFUPM under physics research group projects RG1502-1 and RG1502-2. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (BVD). ; |
Approved |
Most recent IF: 2.649 |
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Call Number |
UA @ lucian @ c:irua:153620UA @ admin @ c:irua:153620 |
Serial |
5086 |
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Permanent link to this record |
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Author |
Abdullah, H.M.; Van Duppen, B.; Zarenia, M.; Bahlouli, H.; Peeters, F.M. |
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Title |
Quantum transport across van der Waals domain walls in bilayer graphene |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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Volume |
29 |
Issue |
42 |
Pages |
425303 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Bilayer graphene can exhibit deformations such that the two graphene sheets are locally detached from each other resulting in a structure consisting of domains with different van der Waals inter-layer coupling. Here we investigate how the presence of these domains affects the transport properties of bilayer graphene. We derive analytical expressions for the transmission probability, and the corresponding conductance, across walls separating different inter-layer coupling domains. We find that the transmission can exhibit a valley-dependent layer asymmetry and that the domain walls have a considerable effect on the chiral tunnelling properties of the charge carriers. We show that transport measurements allow one to obtain the strength with which the two layers are coupled. We perform numerical calculations for systems with two domain walls and find that the availability of multiple transport channels in bilayer graphene significantly modifies the conductance dependence on inter-layer potential asymmetry. |
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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 |
London |
Editor |
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Language |
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Wos |
000410958400001 |
Publication Date |
2017-07-24 |
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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 |
|
Series Issue |
|
Edition |
|
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|
ISSN |
0953-8984 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.649 |
Times cited |
15 |
Open Access |
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|
Notes |
; HMA and HB acknowledge the Saudi Center for Theoretical Physics (SCTP) for their generous support and the support of KFUPM under physics research group projects RG1502-1 and RG1502-2. This work is supported by the Flemish Science Foundation (FWO-VI) by a post-doctoral fellowship (BVD). ; |
Approved |
Most recent IF: 2.649 |
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Call Number |
UA @ lucian @ c:irua:146664 |
Serial |
4793 |
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Permanent link to this record |
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Author |
Rønnow, T.F.; Pedersen, T.G.; Partoens, B. |
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Title |
Biexciton binding energy in fractional dimensional semiconductors |
Type |
A1 Journal article |
|
Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
85 |
Issue |
4 |
Pages |
045412-045412,7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Biexcitons in fractional dimensional spaces are studied using variational quantum Monte Carlo. We investigate the biexciton binding energy as a function of the electron-hole mass fraction sigma as well as study the dimensional dependence of biexcitons for sigma = 0 and sigma = 1. As our first application of this model we treat the H(2) molecule in two and three dimensions. Next we investigate biexcitons in carbon nanotubes within the fractional dimensional model. To this end we find a relation between the nanotube radius and the effective dimension. The results of both applications are compared with results obtained using different models and we find a reasonable agreement. Within the fractional dimensional model we find that the biexciton binding energy in carbon nanotubes accurately scales as E(B)(r,epsilon) = 1280 meV angstrom/(r epsilon), as a function of radius r and the dielectric screening epsilon. |
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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 |
000298922200008 |
Publication Date |
2012-01-06 |
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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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
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|
Notes |
; ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:96234 |
Serial |
231 |
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Permanent link to this record |
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Author |
Govaerts, K.; Park, K.; De Beule, C.; Partoens, B.; Lamoen, D. |
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Title |
Effect of Bi bilayers on the topological states of Bi2Se3 : a first-principles study |
Type |
A1 Journal article |
|
Year |
2014 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
|
|
Volume |
90 |
Issue |
15 |
Pages |
155124 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
Bi2Se3 is a three-dimensional topological insulator which has been extensively studied because it has a single Dirac cone on the surface, inside a relatively large bulk band gap. However, the effect of two-dimensional topological insulator Bi bilayers on the properties of Bi2Se3 and vice versa, has not been explored much. Bi bilayers are often present between the quintuple layers of Bi2Se3, since (Bi2)n(Bi2Se3)m form stable ground-state structures. Moreover, Bi2Se3 is a good substrate for growing ultrathin Bi bilayers. By first-principles techniques, we first show that there is no preferable surface termination by either Bi or Se. Next, we investigate the electronic structure of Bi bilayers on top of, or inside a Bi2Se3 slab. If the Bi bilayers are on top, we observe a charge transfer to the quintuple layers that increases the binding energy of the surface Dirac cones. The extra states, originating from the Bi bilayers, were declared to form a topological Dirac cone, but here we show that these are ordinary Rashba-split states. This result, together with the appearance of a new Dirac cone that is localized slightly deeper, might necessitate the reinterpretation of several experimental results. When the Bi bilayers are located inside the Bi2Se3 slab, they tend to split the slab into two topological insulators with clear surface states. Interface states can also be observed, but an energy gap persists because of strong coupling between the neighboring quintuple layers and the Bi bilayers. |
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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 |
000343773200001 |
Publication Date |
2014-10-20 |
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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 |
|
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 |
30 |
Open Access |
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Notes |
; We gratefully acknowledge financial support from the Research Foundation – Flanders (FWO-Vlaanderen). K.G. thanks the University of Antwerp for a Ph.D. fellowship. C.D.B. is an aspirant of the Flemish Science Foundation. This work was carried out using the HPC infrastructure at the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center VSC, supported financially by the Hercules Foundation and the Flemish Government (EWI Department). K.P. was supported by U.S. National Science Foundation Grant No. DMR-1206354. ; |
Approved |
Most recent IF: 3.836; 2014 IF: 3.736 |
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Call Number |
UA @ lucian @ c:irua:119527 |
Serial |
800 |
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Permanent link to this record |
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Author |
Hai, G.-Q.; Peeters, F.M. |
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Title |
Hamiltonian of a many-electron system with single-electron and electron-pair states in a two-dimensional periodic potential |
Type |
A1 Journal article |
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Year |
2015 |
Publication |
European physical journal : B : condensed matter and complex systems |
Abbreviated Journal |
Eur Phys J B |
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Volume |
88 |
Issue |
88 |
Pages |
20 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Based on the metastable electron-pair energy band in a two-dimensional (2D) periodic potential obtained previously by Hai and Castelano [J. Phys.: Condens. Matter 26, 115502 (2014)], we present in this work a Hamiltonian of many electrons consisting of single electrons and electron pairs in the 2D system. The electron-pair states are metastable of energies higher than those of the single-electron states at low electron density. We assume two different scenarios for the single-electron band. When it is considered as the lowest conduction band of a crystal, we compare the obtained Hamiltonian with the phenomenological model Hamiltonian of a boson-fermion mixture proposed by Friedberg and Lee [Phys. Rev. B 40, 6745 (1989)]. Single-electron-electron-pair and electron-pair-electron-pair interaction terms appear in our Hamiltonian and the interaction potentials can be determined from the electron-electron Coulomb interactions. When we consider the single-electron band as the highest valence band of a crystal, we show that holes in this valence band are important for stabilization of the electron-pair states in the 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 |
Berlin |
Editor |
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Language |
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Wos |
000347776800005 |
Publication Date |
2015-01-10 |
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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 |
1434-6028;1434-6036; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
1.461 |
Times cited |
2 |
Open Access |
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Notes |
; This work was supported by FAPESP and CNPq (Brazil). ; |
Approved |
Most recent IF: 1.461; 2015 IF: 1.345 |
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Call Number |
c:irua:125317 |
Serial |
1406 |
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Permanent link to this record |
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Author |
Vagov, A.V.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Peeters, F.M. |
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Title |
Extended Ginzburg-Landau formalism : systematic expansion in small deviation from the critical temperature |
Type |
A1 Journal article |
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Year |
2012 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
85 |
Issue |
1 |
Pages |
014502-014502,17 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Based on the Gor'kov formalism for a clean s-wave superconductor, we develop an extended version of the single-band Ginzburg-Landau (GL) theory by means of a systematic expansion in the deviation from the critical temperature T(c), i.e., tau = 1 – T/T(c). We calculate different contributions to the order parameter and the magnetic field: the leading contributions (proportional to tau(1/2) in the order parameter and. t in the magnetic field) are controlled by the standard GL theory, while the next-to-leading terms (proportional to tau(3/2) in the gap and proportional to tau(2) in the magnetic field) constitute the extended GL (EGL) approach. We derive the free-energy functional for the extended formalism and the corresponding expression for the current density. To illustrate the usefulness of our formalism, we calculate, in a semianalytical form, the temperature-dependent correction to the GL parameter at which the surface energy becomes zero, and analytically, the temperature dependence of the thermodynamic critical field. We demonstrate that the EGL formalism is not just a mathematical extension to the theory: variations of both the gap and the thermodynamic critical field with temperature calculated within the EGL theory are found in very good agreement with the full BCS results down to low temperatures, which dramatically improves the applicability of the formalism compared to its standard predecessor. |
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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 |
000298985100002 |
Publication Date |
2012-01-10 |
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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 |
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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 |
36 |
Open Access |
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Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). A. V. V. is grateful to V. Zalipaev for important comments. A. A. S. thanks W. Pogosov for helpful notes. Discussions with E. H. Brandt and A. Perali are appreciated. ; |
Approved |
Most recent IF: 3.836; 2012 IF: 3.767 |
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Call Number |
UA @ lucian @ c:irua:96232 |
Serial |
1155 |
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Permanent link to this record |
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Author |
Szaszko-Bogar, V.; Foeldi, P.; Peeters, F.M. |
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Title |
Oscillating spin-orbit interaction as a source of spin-polarized wavepackets in two-terminal nanoscale devices |
Type |
A1 Journal article |
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Year |
2014 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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Volume |
26 |
Issue |
13 |
Pages |
135302 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Ballistic transport through nanoscale devices with time-dependent Rashba-type spin- orbit interaction (SOI) can lead to spin-polarized wavepackets that appear even for completely unpolarized input. The SOI that oscillates in a finite domain generates density and spin polarization fluctuations that leave the region as propagating waves. In particular, spin polarization has space and time dependence even in regions without SOI. Our results are based on an analytical solution of the time-dependent Schrodinger equation. The relevant Floquet quasi-energies that are obtained appear in the energy spectrum of both the transmitted and the reflected waves. |
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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 |
London |
Editor |
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Language |
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Wos |
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Publication Date |
0000-00-00 |
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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 |
0953-8984 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.649 |
Times cited |
|
Open Access |
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Notes |
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Approved |
Most recent IF: 2.649; 2014 IF: 2.346 |
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Call Number |
UA @ lucian @ c:irua:116844 |
Serial |
2533 |
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Permanent link to this record |
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Author |
Wang, X.F.; Vasilopoulos, P.; Peeters, F.M. |
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Title |
Spin-current modulation and square-wave transmission through periodically stubbed electron waveguides |
Type |
A1 Journal article |
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Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
65 |
Issue |
16 |
Pages |
165217 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Ballistic spin transport through waveguides, with symmetric or asymmetric double stubs attached to them periodically, is studied systematically in the presence of a weak spin-orbit coupling that makes the electrons precess. By an appropriate choice of the waveguide length and of the stub parameters injected spin-polarized electrons can be blocked completely and the transmission shows a periodic and nearly-square-type behavior, with values 1 and 0, with wide gaps when only one mode is allowed to propagate in the waveguide. A similar behavior is possible for a certain range of the stub parameters even when two modes can propagate in the waveguide and the conductance is doubled. Such a structure is a good candidate for establishing a realistic spin transistor. A further modulation of the spin current can be achieved by inserting defects in a finite-number stub superlattice. Finite-temperature effects on the spin conductance are also considered. |
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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 |
000175325000061 |
Publication Date |
2002-07-27 |
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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 |
0163-1829;1095-3795; |
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 |
112 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
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Call Number |
UA @ lucian @ c:irua:95128 |
Serial |
3082 |
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Permanent link to this record |
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Author |
Vasilopoulos, P.; Molnar, B.; Peeters, F.M. |
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Title |
Magnetoconductance through a chain of rings in the presence of spin-orbit interaction |
Type |
A1 Journal article |
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Year |
2004 |
Publication |
International journal of modern physics: B: condensed matter physics, statistical physics, applied physics |
Abbreviated Journal |
Int J Mod Phys B |
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Volume |
18 |
Issue |
27-29 |
Pages |
3661-3664 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Ballistic electron transport through a finite chain of quantum circular rings is studied in the presence of the Rashba coupling, of strength a, and of a perpendicular magnetic field B. The transmission and reflection coefficients for a single ring, obtained analytically, help obtain the conductance through a chain of rings as a function of the strength a, the field B, and of the wave vector k of the incident electron. Due to destructive spin interferences caused by the Rashba coupling the chain can be totally opaque for certain ranges of k the width of which depends on values of a and B. Outside these ranges the conductance oscillates with high values between e(2)/h and 2e(2)/h. The effect of a periodic modulation of a or B on the conductance gaps is investigated. A periodic, square-wave conductance pattern, pertinent to the development of the spin transistor, results within wide stripes in the parameter space spanned by k, a, and B. Finite temperatures smoothen the square-wave profile of the conductance but do not alter its periodic character. |
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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 |
Singapore |
Editor |
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Language |
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Wos |
000227140200042 |
Publication Date |
2005-04-12 |
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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 |
0217-9792;1793-6578; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
0.736 |
Times cited |
2 |
Open Access |
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Notes |
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Approved |
Most recent IF: 0.736; 2004 IF: 0.361 |
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Call Number |
UA @ lucian @ c:irua:94787 |
Serial |
1914 |
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Permanent link to this record |
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Author |
Neek-Amal, M.; Peeters, F.M. |
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Title |
Graphene nanoribbons subjected to axial stress |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
82 |
Issue |
8 |
Pages |
085432-085432,6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Atomistic simulations are used to study the bending of rectangular graphene nanoribbons subjected to axial stress both for free boundary and supported boundary conditions. The shapes of the deformations of the buckled graphene nanoribbons, for small values of the stress, are sine waves where the number of nodal lines depend on the longitudinal size of the system and the applied boundary condition. The buckling strain for the supported boundary condition is found to be independent of the longitudinal size and estimated to be 0.86%. From a calculation of the free energy at finite temperature we find that the equilibrium projected two-dimensional area of the graphene nanoribbon is less than the area of a flat sheet. At the optimum length the boundary strain for the supported boundary condition is 0.48%. |
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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 |
000281065100007 |
Publication Date |
2010-08-20 |
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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 |
1098-0121;1550-235X; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
92 |
Open Access |
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|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Belgian Science Policy (IAP). ; |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
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Call Number |
UA @ lucian @ c:irua:84583 |
Serial |
1373 |
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Permanent link to this record |
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Author |
Zarenia, M.; Pereira, J.M.; Farias, G.A.; Peeters, F.M. |
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Title |
Chiral states in bilayer graphene : magnetic field dependence and gap opening |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
84 |
Issue |
12 |
Pages |
125451-125451,13 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
At the interface of electrostatic potential kink profiles, one-dimensional chiral states are found in bilayer graphene (BLG). Such structures can be created by applying an asymmetric potential to the upper and the lower layers of BLG. We found the following: (i) due to the strong confinement by the single kink profile, the unidirectional states are only weakly affected by a magnetic field; (ii) increasing the smoothness of the kink potential results in additional bound states, which are topologically different from those chiral states; and (iii) in the presence of a kink-antikink potential, the overlap between the oppositely moving chiral states results in the appearance of crossing and anticrossing points in the energy spectrum. This leads to the opening of tunable minigaps in the spectrum of the unidirectional topological 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 |
000295484300016 |
Publication Date |
2011-09-30 |
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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 |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
50 |
Open Access |
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|
Notes |
; This work was supported by the Flemish Science Foundation (FWO-VI), the Belgian Science Policy (IAP), the European Science Foundation (ESF) under the EUROCORES program EuroGRAPHENE (project CONGRAN), the Brazilian agency CNPq (Pronex), and the bilateral projects between Flanders and Brazil and the collaboration project FWO-CNPq. ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:92915 |
Serial |
358 |
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Permanent link to this record |
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Author |
Sun, M.-H.; Zhou, J.; Hu, Z.-Y.; Chen, L.-H.; Li, L.-Y.; Wang, Y.-D.; Xie, Z.-K.; Turner, S.; Van Tendeloo, G.; Hasan, T.; Su, B.-L. |
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Title |
Hierarchical zeolite single-crystal reactor for excellent catalytic efficiency |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Matter |
Abbreviated Journal |
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Volume |
3 |
Issue |
4 |
Pages |
1226-1245 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
As a size- and shape-selective catalyst, zeolites are widely used in petroleum and fine-chemicals processing. However, their small micropores severely hinder molecular diffusion and are sensitive to coke formation. Hierarchically porous zeolite single crystals with fully interconnected, ordered, and tunable multimodal porosity at macro-, meso-, and microlength scale, like in leaves, offer the ideal solution. However, their synthesis remains highly challenging. Here, we report a versatile confined zeolite crystallization process to achieve these superior properties. Such zeolite single crystals lead to significantly improved mass transport properties by shortening the diffusion length while maintaining shape-selective properties, endowing them with a high efficiency of zeolite crystals, enhanced catalytic activities and lifetime, highly reduced coke formation, and reduced deactivation rate in bulky-molecule reactions and methanol-to-olefins process. Their industrial utilization can lead to the design of innovative and intensified reactors and processes with highly enhanced efficiency and minimum energy consumption. |
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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 |
000581132600021 |
Publication Date |
2020-08-12 |
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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 |
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ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
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Times cited |
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Open Access |
OpenAccess |
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Notes |
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Approved |
Most recent IF: NA |
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Call Number |
UA @ admin @ c:irua:174329 |
Serial |
6727 |
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Permanent link to this record |
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Author |
Vodolazov, D.I.; Peeters, F.M. |
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Title |
Dynamic transitions between metastable states in a superconducting ring |
Type |
A1 Journal article |
|
Year |
2002 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
66 |
Issue |
5 |
Pages |
054537-054537,7 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Applying the time-dependent Ginzburg-Landau equations, transitions between metastable states of a superconducting ring are investigated in the presence of an external magnetic field. It is shown that if the ring exhibits several metastable states at a particular magnetic field, the transition from one metastable state to another one is governed by both the relaxation time of the absolute value of the order parameter tau(\psi\) and the relaxation time of the phase of the order parameter tau(phi). We found that the larger the ratio tau(\psi\)/tau(phi), the closer the final state will be to the absolute minimum of the free energy, i.e., the thermodynamic equilibrium. The transition to the final state occurs through a subsequent set of single phase slips at a particular point along the ring. |
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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 |
000177873000143 |
Publication Date |
2002-08-30 |
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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 |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
3.836 |
Times cited |
34 |
Open Access |
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|
Notes |
|
Approved |
Most recent IF: 3.836; 2002 IF: NA |
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Call Number |
UA @ lucian @ c:irua:94917 |
Serial |
768 |
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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 |
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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 |
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 |
Peeters, F.M.; Riva, C.; Varga, K. |
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Title |
Trions in quantum wells |
Type |
A1 Journal article |
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Year |
2001 |
Publication |
Physica: B : condensed matter |
Abbreviated Journal |
Physica B |
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Volume |
300 |
Issue |
1-4 |
Pages |
139-155 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
An overview is given of our investigation of the energy levels and of the correlation functions of the negatively and positively charged excitons (also called trions) in quantum wells in the presence of a perpendicular magnetic field, A detailed comparison is made with available experimental data in III-V and II-VI semiconductor quantum wells. (C) 2001 Elsevier Science B.V. All rights reserved. |
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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 |
Amsterdam |
Editor |
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Language |
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Wos |
000170850000011 |
Publication Date |
2002-07-25 |
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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 |
0921-4526; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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|
Impact Factor |
1.386 |
Times cited |
31 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 1.386; 2001 IF: 0.663 |
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Call Number |
UA @ lucian @ c:irua:103410 |
Serial |
3734 |
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Permanent link to this record |
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Author |
Gehrke, K.; Moshnyaga, V.; Samwer, K.; Lebedev, O.I.; Verbeeck, J.; Kirilenko, D.; Van Tendeloo, G. |
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Title |
Interface controlled electronic variations in correlated heterostructures |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
82 |
Issue |
11 |
Pages |
113101,1-113101,4 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
An interface modification of (LaCa)MnO3-BaTiO3 superlattices was found to massively influence magnetic and magnetotransport properties. Moreover it determines the crystal structure of the manganite layers, changing it from orthorhombic (Pnma) for the conventional superlattice (cSL), to rhombohedral (R3̅ c) for the modified one (mSL). While the cSL shows extremely nonlinear ac transport, the mSL is an electrically homogeneous material. The observations go beyond an oversimplified picture of dead interface layers and evidence the importance of electronic correlations at perovskite interfaces. |
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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 |
000281643200001 |
Publication Date |
2010-09-07 |
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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 |
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 |
9 |
Open Access |
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|
Notes |
This work was supported by DFG via SFB 602, TPA2. |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
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Call Number |
UA @ lucian @ c:irua:84249UA @ admin @ c:irua:84249 |
Serial |
1691 |
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Permanent link to this record |
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Author |
Vodolazov, D.Y.; Peeters, F.M.; Dubonos, S.V.; Geim, A.K. |
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Title |
Multiple flux jumps and irreversible behavior of thin Al superconducting rings |
Type |
A1 Journal article |
|
Year |
2003 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
67 |
Issue |
5 |
Pages |
054506-6 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
An experimental and theoretical investigation was made of flux jumps and irreversible magnetization curves of mesoscopic Al superconducting rings. In the small magnetic-field region the change of vorticity with magnetic field can be larger than unity. This behavior is connected with the existence of several metastable states of different vorticities. The intentional introduction of a defect in the ring has a large effect on the size of the flux jumps. Calculations based on the time-dependent Ginzburg-Landau model allows us to explain the experimental results semiquantitatively. |
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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 |
000181360300061 |
Publication Date |
2003-02-22 |
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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 |
0163-1829;1095-3795; |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
|
Impact Factor |
3.836 |
Times cited |
49 |
Open Access |
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Notes |
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Approved |
Most recent IF: 3.836; 2003 IF: NA |
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Call Number |
UA @ lucian @ c:irua:102812 |
Serial |
2227 |
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Permanent link to this record |
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Author |
Grujić, M.; Zarenia, M.; Chaves, A.; Tadić, M.; Farias, G.A.; Peeters, F.M. |
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Title |
Electronic and optical properties of a circular graphene quantum dot in a magnetic field : influence of the boundary conditions |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
84 |
Issue |
20 |
Pages |
205441-205441,12 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
An analytical approach, using the Dirac-Weyl equation, is implemented to obtain the energy spectrum and optical absorption of a circular graphene quantum dot in the presence of an external magnetic field. Results are obtained for the infinite-massand zigzag boundary conditions. We found that the energy spectrum of a dot with the zigzag boundary condition exhibits a zero-energy band regardless of the value of the magnetic field, while for the infinite-mass boundary condition, the zero-energy states appear only for high magnetic fields. The analytical results are compared to those obtained from the tight-binding model: (i) we show the validity range of the continuum model and (ii) we find that the continuum model with the infinite-mass boundary condition describes rather well its tight-binding analog, which can be partially attributed to the blurring of the mixed edges by the staggered potential. |
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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 |
000297295400011 |
Publication Date |
2011-11-21 |
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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 |
78 |
Open Access |
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Notes |
; This work was supported by the EuroGraphene programme of the ESF (project CONGRAN), the Ministry of Education and Science of Serbia, the Belgian Science Policy (IAP), the bilateral projects between Flanders and Brazil, the Flemish Science Foundation (FWO-Vl), and the Brazilian Research Council (CNPq). ; |
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:94025 |
Serial |
997 |
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Permanent link to this record |
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Author |
Cassiers, K.; van der Voort, P.; Linssen, T.; Vansant, E.F.; Lebedev, O.; van Landuyt, J. |
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Title |
A counterion-catalyzed (S0H+)(X-I+) pathway toward heat- and steam-stable mesostructured silica assembled from amines in acidic conditions |
Type |
A1 Journal article |
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Year |
2003 |
Publication |
The journal of physical chemistry : B : condensed matter, materials, surfaces, interfaces and biophysical |
Abbreviated Journal |
J Phys Chem B |
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Volume |
107 |
Issue |
16 |
Pages |
3690-3696 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Laboratory of adsorption and catalysis (LADCA) |
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Abstract |
An alternative pathway to assemble mesoporous molecular sieve silicas is developed using nonionic alkylamines and N,N-dimethylalkylamines (SO) as structure-directing agents in acidic conditions. The synthesized mesostructures possess wormhole-like frameworks with pore sizes and pore volumes in the range of 20-90 Angstrom and 0.5-1.3 cm(3)/g, respectively. The formation of the mesophase is controlled by a counterion-mediated mechanism of the type (S(0)H(+))(X(-)I(+)), where S(0)H(+) are protonated water molecules that are hydrogen bonded to the lone electron pairs on the amine surfactant headgroups (S(0)H(+)), X(-) is the counteranion originating from the acid, and I(+) are the positively charged (protonated) silicate species. We found that the stronger the ion X(-) is bonded to S(0)H(+), the more it catalyzes the silica condensation into (S(0)H(+))(X(-)I(+)). Br(-) is shown to be a strong binding anion and therefore a fast silica polymerization promoter compared to Cl(-) resulting in the formation of a higher quality mesophase for the Br(-) syntheses. We also showed that the polymerization rate of the silica, dictated by the counterion, controls the morphology of the mesostructures from nonuniform agglomerated blocks in the case of Br(-) syntheses to spherical particles for the Cl(-) syntheses. Next to many benefits such as low temperature, short synthesis time, and the use of inexpensive, nontoxic, and easily extractable amine templates, the developed materials have a remarkable higher thermal and hydrothermal stability compared to hexagonal mesoporous silica, which is also prepared with nonionic amines but formed through the S(0)I(0) mechanism. |
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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 |
Washington, D.C. |
Editor |
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Language |
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Wos |
000182350200005 |
Publication Date |
2003-04-17 |
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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 |
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Series Issue |
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Edition |
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ISSN |
1520-6106;1520-5207; |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.177 |
Times cited |
9 |
Open Access |
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Notes |
|
Approved |
Most recent IF: 3.177; 2003 IF: 3.679 |
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Call Number |
UA @ lucian @ c:irua:103300 |
Serial |
24 |
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Permanent link to this record |
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Author |
Fang, C.M.; van Huis, M.A.; Jansen, J.; Zandbergen, H.W. |
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Title |
Role of carbon and nitrogen in Fe2C and Fe2N from first-principles calculations |
Type |
A1 Journal article |
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Year |
2011 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
84 |
Issue |
9 |
Pages |
094102-094102,10 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
Although Fe2C and Fe2N are technologically important materials, the exact nature of the chemical bonding of C and N atoms and the related impact on the electronic properties are at present unclear. Here, results of first-principles electronic structure calculations for Fe2X (X = C, N) phases are presented. The electronic structure calculations show that the roles of N and C in iron nitrides and carbides are comparable, and that the X-X interactions have significant impact on electronic properties. Accurate analysis of the spatially resolved differences in electron densities reveals a subtle distinction between the chemical bonding and charge transfer of N and C ions. |
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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 |
000294772800003 |
Publication Date |
2011-09-09 |
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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 |
24 |
Open Access |
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|
Notes |
|
Approved |
Most recent IF: 3.836; 2011 IF: 3.691 |
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Call Number |
UA @ lucian @ c:irua:92327 |
Serial |
2912 |
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Permanent link to this record |
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Author |
Schattschneider, P.; Verbeeck, J.; Mauchamp, V.; Jaouen, M.; Hamon, A.-L. |
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Title |
Real-space simulations of spin-polarized electronic transitions in iron |
Type |
A1 Journal article |
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Year |
2010 |
Publication |
Physical review : B : condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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Volume |
82 |
Issue |
14 |
Pages |
144418-144418,11 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT) |
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Abstract |
After the advent of energy-loss magnetic chiral dichroism (EMCD) in 2006, rapid progress in theoretical understanding and in experimental performance was achieved, recently demonstrating a spatial resolution of better than 2 nm. Similar to the x-ray magnetic circular dichroism technique, EMCD is used to study atom specific magnetic moments. The latest generation of electron microscopes opens the road to the mapping of spin moments on the atomic scale with this method. Here the theoretical background to reach this challenging aim is elaborated. Numerical simulations of the L3 transition in an Fe specimen, based on a combination of the density-matrix approach for inelastic electron scattering with the propagation of the probe electron in the lattice potential indicate the feasibility of single spin mapping in the electron microscope. |
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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 |
000282678900006 |
Publication Date |
2010-10-08 |
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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 |
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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 |
11 |
Open Access |
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|
Notes |
P.S. acknowledges the support of the Austrian Science Fund, Project No. I543-N20. |
Approved |
Most recent IF: 3.836; 2010 IF: 3.774 |
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Call Number |
UA @ lucian @ c:irua:85029UA @ admin @ c:irua:85029 |
Serial |
2832 |
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Permanent link to this record |