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Author |
Simchi, H.; Simchi, M.; Fardmanesh, M.; Peeters, F.M. |
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Title |
Phase transition and field effect topological quantum transistor made of monolayer MoS2 |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Journal of physics : condensed matter |
Abbreviated Journal |
J Phys-Condens Mat |
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| |
Volume |
30 |
Issue |
23 |
Pages |
235303 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study topological phase transitions and topological quantum field effect transistor in monolayer molybdenum disulfide (MoS2) using a two-band Hamiltonian model. Without considering the quadratic (q(2)) diagonal term in the Hamiltonian, we show that the phase diagram includes quantum anomalous Hall effect, quantum spin Hall effect, and spin quantum anomalous Hall effect regions such that the topological Kirchhoff law is satisfied in the plane. By considering the q(2) diagonal term and including one valley, it is shown that MoS2 has a non-trivial topology, and the valley Chern number is non-zero for each spin. We show that the wave function is (is not) localized at the edges when the q(2) diagonal term is added (deleted) to (from) the spin-valley Dirac mass equation. We calculate the quantum conductance of zigzag MoS2 nanoribbons by using the nonequilibrium Green function method and show how this device works as a field effect topological quantum transistor. |
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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 |
000432821600001 |
Publication Date |
2018-04-26 |
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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 |
2 |
Open Access |
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Notes  |
; ; |
Approved |
Most recent IF: 2.649 |
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Call Number |
UA @ lucian @ c:irua:151457UA @ admin @ c:irua:151457 |
Serial |
5035 |
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Author |
Saberi-Pouya, S.; Vazifehshenas, T.; Saleh, M.; Farmanbar, M.; Salavati-fard, T. |
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Title |
Plasmon modes in monolayer and double-layer black phosphorus under applied uniaxial strain |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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| |
Volume |
123 |
Issue |
17 |
Pages |
174301 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We study the effects of an applied in-plane uniaxial strain on the plasmon dispersions of monolayer, bilayer, and double-layer black phosphorus structures in the long-wavelength limit within the linear elasticity theory. In the low-energy limit, these effects can be modeled through the change in the curvature of the anisotropic energy band along the armchair and zigzag directions. We derive analytical relations of the plasmon modes under uniaxial strain and show that the direction of the applied strain is important. Moreover, we observe that along the armchair direction, the changes of the plasmon dispersion with strain are different and larger than those along the zigzag direction. Using the analytical relations of two-layer phosphorene systems, we found that the strain-dependent orientation factor of layers could be considered as a means to control the variations of the plasmon energy. Furthermore, our study shows that the plasmonic collective modes are more affected when the strain is applied equally to the layers compared to the case in which the strain is applied asymmetrically to the layers. We also calculate the effect of strain on the drag resistivity in a double-layer black phosphorus structure and obtain that the changes in the plasmonic excitations, due to an applied strain, are mainly responsible for the predicted results. This study can be readily extended to other anisotropic two-dimensional materials. Published by AIP Publishing. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000431651600014 |
Publication Date |
2018-05-01 |
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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 |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
4 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.068 |
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Call Number |
UA @ lucian @ c:irua:151522UA @ admin @ c:irua:151522 |
Serial |
5037 |
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Author |
Contino, A.; Ciofi, I.; Wu, X.; Asselberghs, I.; Celano, U.; Wilson, C.J.; Tokei, Z.; Groeseneken, G.; Sorée, B. |
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Title |
Modeling of edge scattering in graphene interconnects |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
IEEE electron device letters |
Abbreviated Journal |
Ieee Electr Device L |
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Volume |
39 |
Issue |
7 |
Pages |
1085-1088 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Graphene interconnects are being considered as a promising candidate for beyond CMOS applications, thanks to the intrinsic higher carrier mobility, lower aspect ratio and better reliability with respect to conventional Cu damascene interconnects. However, similarly to Cu, line edge roughness can seriously affect graphene resistance, something which must be taken into account when evaluating the related performance benefits. In this letter, we present a model for assessing the impact of edge scattering on the resistance of graphene interconnects. Our model allows the evaluation of the total mean free path in graphene lines as a function of graphene width, diffusive scattering probability and edge roughness standard deviation and autocorrelation length. We compare our model with other models from literature by benchmarking them using the same set of experimental data. We show that, as opposed to the considered models from literature, our model is capable to describe the mobility drop with scaling caused by significantly rough edges. |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000437087400041 |
Publication Date |
2018-05-07 |
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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 |
0741-3106 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.048 |
Times cited |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.048 |
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Call Number |
UA @ lucian @ c:irua:152465UA @ admin @ c:irua:152465 |
Serial |
5114 |
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Author |
Beckers, A.; Thewissen, M.; Sorée, B. |
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Title |
Energy filtering in silicon nanowires and nanosheets using a geometric superlattice and its use for steep-slope transistors |
Type |
A1 Journal article |
| |
Year |
2018 |
Publication |
Journal of applied physics |
Abbreviated Journal |
J Appl Phys |
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Volume |
124 |
Issue |
14 |
Pages |
144304 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
This paper investigates energy filtering in silicon nanowires and nanosheets by resonant electron tunneling through a geometric superlattice. A geometric superlattice is any kind of periodic geometric feature along the transport direction of the nanowire or nanosheet. Multivalley quantum-transport simulations are used to demonstrate the manifestation of minibands and minibandgaps in the transmission spectra of such a superlattice. We find that the presence of different valleys in the conduction band of silicon favors a nanowire with a rectangular cross section for effective energy filtering. The obtained energy filter can consequently be used in the source extension of a field-effect transistor to prevent high-energy electrons from contributing to the leakage current. Self-consistent Schrodinger-Poisson simulations in the ballistic limit show minimum subthreshold swings of 6 mV/decade for geometric superlattices with indentations. The obtained theoretical performance metrics for the simulated devices are compared with conventional III-V superlatticeFETs and TunnelFETs. The adaptation of the quantum transmitting boundary method to the finite-element simulation of 3-D structures with anisotropic effective mass is presented in Appendixes A and B. Our results bare relevance in the search for steep-slope transistor alternatives which are compatible with the silicon industry and can overcome the power-consumption bottleneck inherent to standard CMOS technologies. Published by AIP Publishing. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
American Institute of Physics |
Place of Publication |
New York, N.Y. |
Editor |
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Language |
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Wos |
000447148100011 |
Publication Date |
2018-10-11 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0021-8979; 1089-7550 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.068 |
Times cited |
3 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.068 |
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Call Number |
UA @ lucian @ c:irua:154729UA @ admin @ c:irua:154729 |
Serial |
5099 |
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Author |
Magnus, W.; Brosens, F. |
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Title |
Occupation numbers in a quantum canonical ensemble : a projection operator approach |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
Physica: A : theoretical and statistical physics |
Abbreviated Journal |
Physica A |
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Volume |
518 |
Issue |
518 |
Pages |
253-264 |
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Keywords |
A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) |
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Abstract |
Recently, we have used a projection operator to fix the number of particles in a second quantization approach in order to deal with the canonical ensemble. Having been applied earlier to handle various problems in nuclear physics that involve fixed particle numbers, the projector formalism was extended to grant access as well to quantum-statistical averages in condensed matter physics, such as particle densities and correlation functions. In this light, the occupation numbers of the subsequent single-particle energy eigenstates are key quantities to be examined. The goal of this paper is (1) to provide a sound extension of the projector formalism directly addressing the occupation numbers as well as the chemical potential, and (2) to demonstrate how the emerging problems related to numerical instability for fermions can be resolved to obtain the canonical statistical quantities for both fermions and bosons. (C) 2018 Elsevier B.V. All rights reserved. |
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Corporate Author |
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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 |
000456359200021 |
Publication Date |
2018-11-28 |
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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 |
0378-4371 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
2.243 |
Times cited |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.243 |
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Call Number |
UA @ admin @ c:irua:157468 |
Serial |
5223 |
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Author |
De Beule, C.; Saniz, R.; Partoens, B. |
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Title |
Crystalline topological states at a topological insulator junction |
Type |
A1 Journal article |
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Year |
2019 |
Publication |
The journal of physics and chemistry of solids |
Abbreviated Journal |
J Phys Chem Solids |
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Volume |
128 |
Issue |
128 |
Pages |
144-151 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
We consider an interface between two strong time-reversal invariant topological insulators having surface states with opposite spin chirality, or equivalently, opposite mirror Chern number. We show that such an interface supports gapless modes that are protected by mirror symmetry. The interface states are investigated with a continuum model for the Bi2Se3 class of topological insulators that takes into account terms up to third order in the crystal momentum, which ensures that the model has the correct symmetry. The model parameters are obtained from ab initio calculations. Finally, we consider the effect of rotational mismatch at the interface, which breaks the mirror symmetry and opens a gap in the interface spectrum. |
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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 |
000472693100013 |
Publication Date |
2018-01-31 |
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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 |
0022-3697 |
ISBN |
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Additional Links |
UA library record; WoS full record |
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Impact Factor |
2.059 |
Times cited |
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Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 2.059 |
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Call Number |
UA @ admin @ c:irua:161391 |
Serial |
5385 |
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Author |
Sabzalipour, A.; Partoens, B. |
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Title |
Anomalous Hall effect in magnetic topological insulators : semiclassical framework |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
100 |
Issue |
3 |
Pages |
035419 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The anomalous Hall effect (AHE) is studied on the surface of a 3D magnetic topological insulator. By applying a modified semiclassical framework, all three contributions to the AHE, the Berry curvature effect, the side jump effect and the skew scattering effects are systematically treated, and analytical expressions for the conductivities are obtained in terms of the Fermi level, the spatial orientation of the surface magnetization and the concentration of magnetic and nonmagnetic impurities. We demonstrate that the AHE can change sign by altering the orientation of the surface magnetization, the concentration of the impurities and also the position of the Fermi level, in agreement with recent experimental observations. We show how each contribution to the AHE, or even the whole AHE, can be turned off by properly adjusting the given parameters. For example, one can turn off the anomalous hall conductivity in a system with in-plane magnetization by pushing the system into the fully metallic regime. |
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Corporate Author |
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Place of Publication |
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Editor |
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Language |
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Wos |
000475499200007 |
Publication Date |
2019-07-15 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9969; 2469-9950 |
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 |
2 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:161219 |
Serial |
5406 |
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Author |
Chaves, A.; Neilson, D. |
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Title |
Exotic state seen at high temperatures |
Type |
Editorial |
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Year |
2019 |
Publication |
Nature |
Abbreviated Journal |
Nature |
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Volume |
574 |
Issue |
7776 |
Pages |
39-40 |
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Keywords |
Editorial; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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Abstract |
The phenomenon of Bose-Einstein condensation is typically limited to extremely low temperatures. The effect has now been spotted at much higher temperatures for particles called excitons in atomically thin semiconductors. |
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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 |
000488832500022 |
Publication Date |
2019-10-02 |
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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 |
0028-0836 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
40.137 |
Times cited |
2 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 40.137 |
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Call Number |
UA @ admin @ c:irua:163739 |
Serial |
5413 |
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Author |
Yuan, H.F.; Xu, W.; Zhao, X.N.; Song, D.; Zhang, G.R.; Xiao, Y.M.; Ding, L.; Peeters, F.M. |
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Title |
Quantum and transport mobilities of a Na3Bi-based three-dimensional Dirac system |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
99 |
Issue |
23 |
Pages |
235303 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The electronic and transport properties of a three-dimensional (3D) Dirac system are investigated theoretically, which is motivated by recent experimental measurements on quantum and transport mobilities in the 3D Dirac semimetal Na3Bi by J. Xiong et al. [Science 350, 413 (2015); Europhys. Lett. 114, 27002 (2016)]. The electron Hamiltonian is taken from a simplified k center dot p approach. From the obtained electronic band structure and the Fermi energy, we explain why the anomalous effect induced by the chiral anomaly and the Berry curvature in the energy band can be observed experimentally in magnetotransport coefficients in both low-and high-density samples. Moreover, the quantum and transport mobilities are calculated on the basis of the momentum-balance equation derived from a semiclassical Boltzmann equation with the electron-impurity interaction. The quantum and transport mobilities obtained from this study agree both qualitatively and quantitatively with those measured experimentally. We also examine the electron mobilities along different crystal directions in Na3Bi and find them largely anisotropic. The theoretical findings from this work can be helpful in gaining an in-depth understanding of the experimental results and of the basic electronic and transport properties of newly developed 3D Dirac systems. |
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Corporate Author |
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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 |
000471983500006 |
Publication Date |
2019-06-17 |
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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 |
2469-9969; 2469-9950 |
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 |
1 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
UA @ admin @ c:irua:161329 |
Serial |
5425 |
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Author |
Bafekry, A.; Ghergherehchi, M.; Shayesteh, S.F. |
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Title |
Tuning the electronic and magnetic properties of antimonene nanosheets via point defects and external fields: first-principles calculations |
Type |
A1 Journal article |
| |
Year |
2019 |
Publication |
Physical chemistry, chemical physics |
Abbreviated Journal |
Phys Chem Chem Phys |
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Volume |
21 |
Issue |
20 |
Pages |
10552-10566 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Defects are inevitably present in materials, and their existence in a material strongly affects its fundamental physical properties. We have systematically investigated the effects of surface adsorption, substitutional impurities, defect engineering, an electric field and strain engineering on the structural, electronic and magnetic properties of antimonene nanosheets, using spin-polarized density functional calculations based on first-principles. The adsorption or substitution of atoms can locally modify the atomic and electronic structures as well as induce a variety of electronic behaviors including metal, half-metal, ferromagnetic metal, dilute magnetic semiconductor and spin-glass semiconductor. Our calculations show that the presence of typical defects (vacancies and Stone-Wales defect) in antimonene affects the geometrical symmetry as well as the band gap in the electronic band structure and induces magnetism to antimonene. Moreover, by applying an external electric field and strain (uniaxial and biaxial), the electronic structure of antimonene can be easily modified. The calculation results presented in this paper provide a fundamental insight into the tunable nature of the electronic properties of antimonene, supporting its promise for use in future applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000476561000031 |
Publication Date |
2019-04-25 |
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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 |
1463-9076; 1463-9084 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
4.123 |
Times cited |
17 |
Open Access |
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Notes |
; ; |
Approved |
Most recent IF: 4.123 |
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Call Number |
UA @ admin @ c:irua:161945 |
Serial |
5430 |
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Author |
Bafekry, A.; Stampfl, C.; Shayesteh, S.F. |
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Title |
A first-principles study of C3N nanostructures : control and engineering of the electronic and magnetic properties of nanosheets, tubes and ribbons |
Type |
A1 Journal article |
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Year |
2020 |
Publication |
Chemphyschem |
Abbreviated Journal |
Chemphyschem |
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Volume |
21 |
Issue |
2 |
Pages |
164-174 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
Using first-principles calculations we systematically investigate the atomic, electronic and magnetic properties of novel two-dimensional materials (2DM) with a stoichiometry C3N which has recently been synthesized. We investigate how the number of layers affect the electronic properties by considering monolayer, bilayer and trilayer structures, with different stacking of the layers. We find that a transition from semiconducting to metallic character occurs which could offer potential applications in future nanoelectronic devices. We also study the affect of width of C3N nanoribbons, as well as the radius and length of C3N nanotubes, on the atomic, electronic and magnetic properties. Our results show that these properties can be modified depending on these dimensions, and depend markedly on the nature of the edge states. Functionalization of the nanostructures by the adsorption of H adatoms is found induce metallic, half-metallic, semiconducting and ferromagnetic behavior, which offers an approach to tailor the properties, as can the application of strain. Our calculations give insight into this new family of C3N nanostructures, which reveal unusual electronic and magnetic properties, and may have great potential in applications such as sensors, electronics and optoelectronic at the nanoscale. |
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Address |
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Corporate Author |
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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 |
000503453100001 |
Publication Date |
2019-11-09 |
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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 |
1439-4235 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.9 |
Times cited |
27 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 2.9; 2020 IF: 3.075 |
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| |
Call Number |
UA @ admin @ c:irua:165045 |
Serial |
6282 |
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| Permanent link to this record |
| |
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| |
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Author |
Kenawy, A.; Magnus, W.; Milošević, M.V.; Sorée, B. |
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| |
Title |
Electronically tunable quantum phase slips in voltage-biased superconducting rings as a base for phase-slip flux qubits |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Superconductor Science & Technology |
Abbreviated Journal |
Supercond Sci Tech |
|
| |
Volume |
33 |
Issue |
12 |
Pages |
125002 |
|
| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
|
| |
Abstract |
Quantum phase slips represent a coherent mechanism to couple flux states of a superconducting loop. Since their first direct observation, there have been substantial developments in building charge-insensitive quantum phase-slip circuits. At the heart of these devices is a weak link, often a nanowire, interrupting a superconducting loop. Owing to the very small cross-sectional area of such a nanowire, quantum phase slip rates in the gigahertz range can be achieved. Instead, here we present the use of a bias voltage across a superconducting loop to electrostatically induce a weak link, thereby amplifying the rate of quantum phase slips without physically interrupting the loop. Our simulations reveal that the bias voltage modulates the free energy barrier between subsequent flux states in a very controllable fashion, providing a route towards a phase-slip flux qubit with a broadly tunable transition frequency. |
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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 |
|
Wos |
000577207000001 |
Publication Date |
2020-09-16 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0953-2048 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.6 |
Times cited |
4 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.6; 2020 IF: 2.878 |
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| |
Call Number |
UA @ admin @ c:irua:172643 |
Serial |
6503 |
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| Permanent link to this record |
| |
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| |
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Author |
Mao, J.; Milovanović, S.P.; Andelkovic, M.; Lai, X.; Cao, Y.; Watanabe, K.; Taniguchi, T.; Covaci, L.; Peeters, F.M.; Geim, A.K.; Jiang, Y.; Andrei, E.Y. |
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| |
Title |
Evidence of flat bands and correlated states in buckled graphene superlattices |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Nature |
Abbreviated Journal |
Nature |
|
| |
Volume |
584 |
Issue |
7820 |
Pages |
215-220 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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| |
Abstract |
Two-dimensional atomic crystals can radically change their properties in response to external influences, such as substrate orientation or strain, forming materials with novel electronic structure(1-5). An example is the creation of weakly dispersive, 'flat' bands in bilayer graphene for certain 'magic' angles of twist between the orientations of the two layers(6). The quenched kinetic energy in these flat bands promotes electron-electron interactions and facilitates the emergence of strongly correlated phases, such as superconductivity and correlated insulators. However, the very accurate fine-tuning required to obtain the magic angle in twisted-bilayer graphene poses challenges to fabrication and scalability. Here we present an alternative route to creating flat bands that does not involve fine-tuning. Using scanning tunnelling microscopy and spectroscopy, together with numerical simulations, we demonstrate that graphene monolayers placed on an atomically flat substrate can be forced to undergo a buckling transition(7-9), resulting in a periodically modulated pseudo-magnetic field(10-14), which in turn creates a 'post-graphene' material with flat electronic bands. When we introduce the Fermi level into these flat bands using electrostatic doping, we observe a pseudogap-like depletion in the density of states, which signals the emergence of a correlated state(15-17). This buckling of two-dimensional crystals offers a strategy for creating other superlattice systems and, in particular, for exploring interaction phenomena characteristic of flat bands. Buckled monolayer graphene superlattices are found to provide an alternative to twisted bilayer graphene for the study of flat bands and correlated states in a carbon-based material. |
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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 |
000559831500012 |
Publication Date |
2020-08-12 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
0028-0836 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
64.8 |
Times cited |
75 |
Open Access |
Not_Open_Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 64.8; 2020 IF: 40.137 |
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| |
Call Number |
UA @ admin @ c:irua:171150 |
Serial |
6513 |
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| Permanent link to this record |
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| |
|
Author |
Bafekry, A. |
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| |
Title |
Graphene-like BC₆N single-layer: tunable electronic and magnetic properties via thickness, gating, topological defects, and adatom/molecule |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physica E-Low-Dimensional Systems & Nanostructures |
Abbreviated Journal |
Physica E |
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| |
Volume |
118 |
Issue |
|
Pages |
113850-15 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
By using density functional theory-based first-principles calculations, we investigate the structural, electronic, optical, and transport properties of pristine single-layer BC6N. Under different external actions and functionalization. Increasing the thickness of the structure results in a decrease of the band gap. Applying a perpendicular electric field decreases the band gap and a semiconductor-to-topological insulator transition is revealed. Uniaxial and biaxial strains of +8% result in a semiconductor-to-metal transition. Nanoribbons of BC6N having zigzag edge with even (odd) values of widths, become metal (semiconductor), while the armchair edge nanoribbons exhibit robust semiconducting behavior. In addition, we systematically investigate the effect of surface adatom and molecule, substitutional impurity and defect engineering on the electronic properties of single-layer BC6N and found transitions from metal to half-metal, to ferromagnetic metal, to dilute magnetic semiconductor, and even to spin-glass semiconductor. Furthermore we found that, topological defects including vacancies and Stone–Wales type, induce magnetism in single-layer BC6N. |
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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 |
000515321700032 |
Publication Date |
2019-12-04 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
1386-9477 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.3 |
Times cited |
30 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.3; 2020 IF: 2.221 |
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| |
Call Number |
UA @ admin @ c:irua:169750 |
Serial |
6530 |
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| Permanent link to this record |
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| |
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Author |
Van der Donck, M.; Zarenia, M.; Peeters, F.M. |
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| |
Title |
Reply to “Comment on `Excitons, trions, and biexcitons in transition-metal dichalcogenides: Magnetic-field dependence'” |
Type |
Editorial |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
101 |
Issue |
12 |
Pages |
127402 |
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| |
Keywords |
Editorial; Condensed Matter Theory (CMT) |
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| |
Abstract |
In the Comment, the authors state that the separation of the relative and center of mass variables in our work is not correct. Here we point out that there is a typographical error, i.e., qi instead of -e, in two of our equations which, when corrected, makes the Comment redundant. Within the ansatzes mentioned in our paper all our results are correct, in contrast to the claims of the Comment. |
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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 |
000519990800011 |
Publication Date |
2020-03-18 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record |
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| |
Impact Factor |
3.7 |
Times cited |
|
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:167680 |
Serial |
6594 |
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| Permanent link to this record |
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| |
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Author |
Litzius, K.; Leliaert, J.; Bassirian, P.; Rodrigues, D.; Kromin, S.; Lemesh, I.; Zazvorka, J.; Lee, K.-J.; Mulkers, J.; Kerber, N.; Heinze, D.; Keil, N.; Reeve, R.M.; Weigand, M.; Van Waeyenberge, B.; Schuetz, G.; Everschor-Sitte, K.; Beach, G.S.D.; Klaeui, M. |
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Title |
The role of temperature and drive current in skyrmion dynamics |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Nature Electronics |
Abbreviated Journal |
|
|
| |
Volume |
3 |
Issue |
1 |
Pages |
30-36 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Magnetic skyrmions are topologically stabilized nanoscale spin structures that could be of use in the development of future spintronic devices. When a skyrmion is driven by an electric current it propagates at an angle relative to the flow of current-known as the skyrmion Hall angle (SkHA)-that is a function of the drive current. This drive dependence, as well as thermal effects due to Joule heating, could be used to tailor skyrmion trajectories, but are not well understood. Here we report a study of skyrmion dynamics as a function of temperature and drive amplitude. We find that the skyrmion velocity depends strongly on temperature, while the SkHA does not and instead evolves differently in the low- and high-drive regimes. In particular, the maximum skyrmion velocity in ferromagnetic devices is limited by a mechanism based on skyrmion surface tension and deformation (where the skyrmion transitions into a stripe). Our mechanism provides a complete description of the SkHA in ferromagnetic multilayers across the full range of drive strengths, illustrating that skyrmion trajectories can be engineered for device applications. An analysis of skyrmion dynamics at different temperatures and electric drive currents is used to develop a complete description of the skyrmion Hall angle in ferromagnetic multilayers from the creep to the flow regime and illustrates that skyrmion trajectories can be engineered for device applications. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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| |
Language |
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Wos |
000510860800012 |
Publication Date |
2020-01-24 |
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| |
Series Editor |
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Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
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| |
ISSN |
|
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
|
Times cited |
11 |
Open Access |
|
|
| |
Notes |
; ; |
Approved |
Most recent IF: NA |
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| |
Call Number |
UA @ admin @ c:irua:167863 |
Serial |
6625 |
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| Permanent link to this record |
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| |
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Author |
Bafekry, A.; Akgenc, B.; Shayesteh, S.F.; Mortazavi, B. |
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| |
Title |
Tunable electronic and magnetic properties of graphene/carbon-nitride van der Waals heterostructures |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
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| |
Volume |
505 |
Issue |
|
Pages |
144450-144459 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
In this paper, we explore the electronic properties of C3N, C3N4 and C4N3 and graphene (Gr) van der Waals heterostructures by conducing extensive first-principles calculations. The acquired results show that these heterostructures can show diverse electronic properties, such as the metal (Gr on C3N), semiconductor with narrow band gap (Gr on C3N4) and ferromagnetic-metal (Gr on C4N3). We furthermore explored the effect of vacancies, atom substitution, topological, antisite and Stone-Wales defects on the structural and electronic properties of considered heterostructures. Our results show that the vacancy defects introduce localized states near the Fermi level and create a local magnetic moment. The Gr/C3N heterostructures with the single and double vacancy defects exhibit a ferromagnetic-metal, while Stone-Wales defects show an indirect semiconductor with the band gap of 0.2 eV. The effects of adsorption and insertion of O, C, Be, Cr, Fe and Co atoms on the electronic properties of Gr/C3N have been also elaborately studied. Our results highlight that the electronic and magnetic properties of garphene/carbon-nitride lateral heterostructures can be effectively modified by point defects and impurities. |
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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 |
000510846500052 |
Publication Date |
2019-11-18 |
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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 |
0169-4332 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.7 |
Times cited |
26 |
Open Access |
|
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| |
Notes |
; ; |
Approved |
Most recent IF: 6.7; 2020 IF: 3.387 |
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| |
Call Number |
UA @ admin @ c:irua:167732 |
Serial |
6638 |
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| Permanent link to this record |
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| |
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Author |
Bafekry, A.; Neek-Amal, M. |
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| |
Title |
Tuning the electronic properties of graphene-graphitic carbon nitride heterostructures and heterojunctions by using an electric field |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
101 |
Issue |
8 |
Pages |
085417-10 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Integration of graphene-based two-dimensional materials is essential for nanoelectronics applications. Using density-functional theory, we systematically investigate the electronic properties of vertically stacked graphene-graphitic carbon nitrides (GE/GCN). We also studied the covalently lateral stitched graphene-graphitic carbon nitrides (GE-GCN heterojunctions). The effects of perpendicular electric field on the electronic properties of six different heterostructures, i.e., (i) one layer of GE on top of a layer of CnNm with (n, m) = (3,1), (3,4), and (4,3) and (ii) three heterostructures CnNm/Cn'Nm', where (n, m) not equal (n', m') are elucidated. The most important calculated features are (i) the systems GE/C3N4, C3N/C3N4, GE-C3N, GE-C4N3, and C3N-C3N4 exhibit semiconducting characteristics having small band gaps of Delta(0)=20, 250, 100, 100, 80 meV, respectively while (ii) the systems GE/C4N3, C3N/C4N3, and C3N-C4N3 show ferromagnetic-metallic properties. In particular, we found that, in semiconducting heterostructures, the band gap increases nontrivially with increasing the absolute value of the applied perpendicular electric field. This work is useful for designing heterojunctions and heterostructures made of graphene and other two-dimensional materials such as those proposed in recent experiments [X. Liu and M. C. Hersam Sci. Adv. 5, 6444 (2019)]. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000515659700007 |
Publication Date |
2020-02-26 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
3.7 |
Times cited |
24 |
Open Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:167760 |
Serial |
6640 |
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| Permanent link to this record |
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| |
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Author |
Bafekry, A.; Neek-Amal, M.; Peeters, F.M. |
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| |
Title |
Two-dimensional graphitic carbon nitrides: strain-tunable ferromagnetic ordering |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
101 |
Issue |
16 |
Pages |
165407-165408 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
Using first-principle calculations, we systematically study strain tuning of the electronic properties of two- dimensional graphitic carbon nitride nanosheets with empirical formula CnNm. We found the following: (i) the ferromagnetic ordered state in the metal-free systems (n, m) = (4,3), (10,9), and (14,12) remains stable in the presence of strain of about 6%. However, the system (9,7) loses its ferromagnetic ordering when increasing strain. This is due to the presence of topological defects in the (9,7) system, which eliminates the asymmetry between spin up and spin down of the p(z) orbitals when strain is applied. (ii) By applying uniaxial strain, a band gap opens in systems which are initially gapless. (iii) In semiconducting systems which have an initial gap of about 1 eV, the band gap is closed with applying uniaxial strain. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
|
Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000523630200012 |
Publication Date |
2020-04-06 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
|
| |
ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.7 |
Times cited |
22 |
Open Access |
|
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| |
Notes |
; ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
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| |
Call Number |
UA @ admin @ c:irua:168560 |
Serial |
6643 |
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| Permanent link to this record |
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| |
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Author |
Obeid, M.M.; Bafekry, A.; Rehman, S.U.; Nguyen, C., V. |
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Title |
A type-II GaSe/HfS₂ van der Waals heterostructure as promising photocatalyst with high carrier mobility |
Type |
A1 Journal article |
| |
Year |
2020 |
Publication |
Applied Surface Science |
Abbreviated Journal |
Appl Surf Sci |
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| |
Volume |
534 |
Issue |
|
Pages |
147607 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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| |
Abstract |
In this paper, the electronic, optical, and photocatalytic properties of GaSe/HfS2 heterostructure are studied via first-principles calculations. The stability of the vertically stacked heterobilayers is validated by the binding energy, phonon spectrum, and ab initio molecular dynamics simulation. The results reveal that the most stable GaSe/HfS2 heterobilayer retains a type-II alignment with an indirect bandgap 1.40 eV. As well, the results also show strong optical absorption intensity in the studied heterostructure (1.8 x 10(5) cm(-1)). The calculated hole mobility is 1376 cm(2) V-1 s(-1), while electron mobility reaches 911 cm(2) V-1 s(-1) along the armchair and zigzag directions. By applying an external electric field, the bandgap and band offset of the designed heterostructure can be effectively modified. Remarkably, a stronger external electric field can create nearly free electron states in the vicinity of the bottom of the conduction band, which induces indirect-to-direct bandgap transition as well as a semiconductor-to-metal transition. In contrast, the electronic properties of GaSe/HfS2 heterostructure are predicted to be insensitive to biaxial strain. The current work reveals that GaSe/HfS2 heterostructure is a promising candidate as a novel photocatalytic material for hydrogen generation in the visible range. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
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Editor |
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| |
Language |
|
Wos |
000582367700045 |
Publication Date |
2020-08-20 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
0169-4332 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
|
| |
Impact Factor |
6.7 |
Times cited |
4 |
Open Access |
|
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| |
Notes |
; ; |
Approved |
Most recent IF: 6.7; 2020 IF: 3.387 |
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| |
Call Number |
UA @ admin @ c:irua:174301 |
Serial |
6682 |
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| Permanent link to this record |
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Author |
Jalali, H.; Khoeini, F.; Peeters, F.M.; Neek-Amal, M. |
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Title |
Hydration effects and negative dielectric constant of nano-confined water between cation intercalated MXenes |
Type |
A1 Journal article |
| |
Year |
2021 |
Publication |
Nanoscale |
Abbreviated Journal |
Nanoscale |
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| |
Volume |
13 |
Issue |
2 |
Pages |
922-929 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Using electrochemical methods a profound enhancement of the capacitance of electric double layer capacitor electrodes was reported when water molecules are strongly confined into the two-dimensional slits of titanium carbide MXene nanosheets [A. Sugahara et al., Nat. Commun., 2019, 10, 850]. We study the effects of hydration on the dielectric properties of nanoconfined water and supercapacitance properties of the cation intercalated MXene. A model for the electric double layer capacitor is constructed where water molecules are strongly confined in two-dimensional slits of MXene. We report an abnormal dielectric constant and polarization of nano-confined water between MXene layers. We found that by decreasing the ionic radius of the intercalated cations and in a critical hydration shell radius the capacitance of the system increases significantly (similar or equal to 200 F g(-1)) which can be interpreted as a negative permittivity. This study builds a bridge between the fundamental understanding of the dielectric properties of nanoconfined water and the capability of using MXene films for supercapacitor technology, and in doing so provides a solid theoretical support for recent experiments. |
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Address |
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Corporate Author |
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Thesis |
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| |
Publisher |
|
Place of Publication |
|
Editor |
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| |
Language |
|
Wos |
000610368100035 |
Publication Date |
2020-12-08 |
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| |
Series Editor |
|
Series Title |
|
Abbreviated Series Title |
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| |
Series Volume |
|
Series Issue |
|
Edition |
|
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| |
ISSN |
2040-3364 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
7.367 |
Times cited |
3 |
Open Access |
Not_Open_Access |
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| |
Notes |
; ; |
Approved |
Most recent IF: 7.367 |
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| |
Call Number |
UA @ admin @ c:irua:176141 |
Serial |
6690 |
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| Permanent link to this record |
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Author |
Nikolaev, A.V.; Lamoen, D.; Partoens, B. |
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Title |
Extension of the basis set of linearized augmented plane wave (LAPW) method by using supplemented tight binding basis functions |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
The journal of chemical physics |
Abbreviated Journal |
J Chem Phys |
|
| |
Volume |
145 |
Issue |
145 |
Pages |
014101 |
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| |
Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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| |
Abstract |
In order to increase the accuracy of the linearized augmented plane wave (LAPW) method, we present a new approach where the plane wave basis function is augmented by two different atomic radial components constructed at two different linearization energies corresponding to two different electron bands (or energy windows). We demonstrate that this case can be reduced to the standard treatment within the LAPW paradigm where the usual basis set is enriched by the basis functions of the tight binding type, which go to zero with zero derivative at the sphere boundary. We show that the task is closely related with the problem of extended core states which is currently solved by applying the LAPW method with local orbitals (LAPW+LO). In comparison with LAPW+LO, the number of supplemented basis functions in our approach is doubled, which opens up a new channel for the extension of the LAPW and LAPW+LO basis sets. The appearance of new supplemented basis functions absent in the LAPW+LO treatment is closely related with the existence of the ul-component in the canonical LAPW method. We discuss properties of additional tight binding basis functions and apply the extended basis set for computation of electron energy bands of lanthanum (face and body centered structures) and hexagonal close packed lattice of cadmium. We demonstrate that the new treatment gives lower total energies in comparison with both canonical LAPW and LAPW+LO, with the energy difference more pronounced for intermediate and poor LAPW basis sets. |
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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 |
000379584700003 |
Publication Date |
2016-07-05 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
|
Edition |
|
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| |
ISSN |
0021-9606 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
2.965 |
Times cited |
11 |
Open Access |
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| |
Notes |
A.V.N. acknowledges useful discussions with B. Verberck, E. V. Tkalya, and A. V. Bibikov. |
Approved |
Most recent IF: 2.965 |
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| |
Call Number |
c:irua:134290 |
Serial |
4099 |
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| Permanent link to this record |
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Author |
Jelić, Ž.L.; Milošević, M.V.; Van de Vondel, J.; Silhanek, A.V. |
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Title |
Stroboscopic phenomena in superconductors with dynamic pinning landscape |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Scientific reports |
Abbreviated Journal |
Sci Rep-Uk |
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| |
Volume |
5 |
Issue |
5 |
Pages |
14604 |
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| |
Keywords |
A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) |
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| |
Abstract |
Introducing artificial pinning centers is a well established strategy to trap quantum vortices and increase the maximal magnetic field and applied electric current that a superconductor can sustain without dissipation. In case of spatially periodic pinning, a clear enhancement of the superconducting critical current arises when commensurability between the vortex configurations and the pinning landscape occurs. With recent achievements in (ultrafast) optics and nanoengineered plasmonics it has become possible to exploit the interaction of light with superconductivity, and create not only spatially periodic imprints on the superconducting condensate, but also temporally periodic ones. Here we show that in the latter case, temporal matching phenomena develop, caused by stroboscopic commensurability between the characteristic frequency of the vortex motion under applied current and the frequency of the dynamic pinning. The matching resonances persist in a broad parameter space, including magnetic field, driving current, or material purity, giving rise to unusual features such as externally variable resistance/impedance and Shapiro steps in current-voltage characteristics. All features are tunable by the frequency of the dynamic pinning landscape. These findings open further exploration avenues for using flashing, spatially engineered, and/or mobile excitations on superconductors, permitting us to achieve advanced functionalities. |
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Address |
Departement de Physique, Universite de Liege, Allee du 6-Aout 17, B-4000 Liege, Belgium |
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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 |
English |
Wos |
000362082500001 |
Publication Date |
2015-10-01 |
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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 |
2045-2322 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
4.259 |
Times cited |
29 |
Open Access |
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| |
Notes |
Acknowledgements: This work was supported by the Methusalem Funding of the Flemish Government, the Research Foundation-Flanders (FWO) and the COST Action MP1201. The work of Ž.L.J. and A.V.S. was partially supported by “Mandat d’Impulsion Scientifique” of the F.R.S.-FNRS. |
Approved |
Most recent IF: 4.259; 2015 IF: 5.578 |
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Call Number |
c:irua:129807 c:irua:129807 |
Serial |
3980 |
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| Permanent link to this record |
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Author |
Adami, O.-A.; Jelić, Ž.L.; Xue, C.; Abdel-Hafiez, M.; Hackens, B.; Moshchalkov, V.V.; Milošević, M.V.; Van de Vondel, J.; Silhanek, A.V. |
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Title |
Onset, evolution, and magnetic braking of vortex lattice instabilities in nanostructured superconducting films |
Type |
A1 Journal article |
| |
Year |
2015 |
Publication |
Physical review: B: condensed matter and materials physics |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
92 |
Issue |
92 |
Pages |
134506 |
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| |
Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
In 1976, Larkin and Ovchinnikov [Zh. Eksp. Teor. Fiz. 68, 1915 (1975) [Sov. Phys.–JETP 41, 960 (1976)]] predicted that vortex matter in superconductors driven by an electrical current can undergo an abrupt dynamic transition from a flux-flow regime to a more dissipative state at sufficiently high vortex velocities. Typically, this transition manifests itself as a large voltage jump at a particular current density, so-called instability current density J∗, which is smaller than the depairing current. By tuning the effective pinning strength in Al films, using an artificial periodic pinning array of triangular holes, we show that a unique and well-defined instability current density exists if the pinning is strong, whereas a series of multiple voltage transitions appear in the relatively weaker pinning regime. This behavior is consistent with time-dependent Ginzburg-Landau simulations, where the multiple-step transition can be unambiguously attributed to the progressive development of vortex chains and subsequently phase-slip lines. In addition, we explore experimentally the magnetic braking effects, caused by a thick Cu layer deposited on top of the superconductor, on the instabilities and the vortex ratchet effect. |
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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 |
000362433200003 |
Publication Date |
2015-10-08 |
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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 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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| |
Impact Factor |
3.836 |
Times cited |
21 |
Open Access |
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Notes |
ACKNOWLEDGMENTS: This work was partially supported by the Fonds de la Recherche Scientifique-FNRS, the Methusalem Funding of the Flemish Government, the Research Foundation-Flanders (FWO), and COST Action MP1201. The work of A.V.S. and Z.L.J. is partially supported by “Mandat d’Impulsion Scientifique” MIS F.4527.13 of the F.R.S.-FNRS. B.H. is an associate researcher of the Fonds de la Recherche Scientifique- FNRS. The authors thank J. Cuppens for the data analysis at the early stage of this work, R. Delamare for his valuable help during the fabrication of the samples, and G. Grimaldi for helpful discussions. |
Approved |
Most recent IF: 3.836; 2015 IF: 3.736 |
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| |
Call Number |
c:irua:128747 |
Serial |
3981 |
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| Permanent link to this record |
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Author |
Vagov, A.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Vinokur, V.M.; Aguiar, J.A.; Peeters, F.M. |
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Title |
Superconductivity between standard types: Multiband versus single-band materials |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
93 |
Issue |
93 |
Pages |
174503 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000375527500001 |
Publication Date |
2016-05-06 |
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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 |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
37 |
Open Access |
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Notes |
Conselho Nacional de Desenvolvimento Científico e Tecnológico, 307552/2012-8 141911/2012-3 ; Fundação de Amparo à Ciência e Tecnologia do Estado de Pernambuco, APQ-0589-1.05/08 ; U.S. Department of Energy; |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @ c:irua:141732 |
Serial |
4480 |
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| Permanent link to this record |
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Author |
Cavalcante, L.S.R.; Chaves, A.; Van Duppen, B.; Peeters, F.M.; Reichman, D.R. |
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Title |
Electrostatics of electron-hole interactions in van der Waals heterostructures |
Type |
A1 Journal article |
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Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
97 |
Issue |
12 |
Pages |
125427 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The role of dielectric screening of electron-hole interaction in van der Waals heterostructures is theoretically investigated. A comparison between models available in the literature for describing these interactions is made and the limitations of these approaches are discussed. A simple numerical solution of Poisson's equation for a stack of dielectric slabs based on a transfer matrix method is developed, enabling the calculation of the electron-hole interaction potential at very low computational cost and with reasonable accuracy. Using different potential models, direct and indirect exciton binding energies in these systems are calculated within Wannier-Mott theory, and a comparison of theoretical results with recent experiments on excitons in two-dimensional materials is discussed. |
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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 |
000427983700007 |
Publication Date |
2018-03-21 |
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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 |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
22 |
Open Access |
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Notes |
Discussions with A. Chernikov and A. Raja are gratefully acknowledged. This work has been financially supported by CNPq, through the PRONEX/FUNCAP, PQ, and Science Without Borders programs, and the FWO-CNPq bilateral program between Brazil and Flanders. B.V.D. acknowledges support from the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. D.R.R. was supported by NSF CHE-1464802. |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @c:irua:150835UA @ admin @ c:irua:150835 |
Serial |
4953 |
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| Permanent link to this record |
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Author |
Callewaert, V.; Saniz, R.; Barbiellini, B.; Bansil, A.; Partoens, B. |
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Title |
Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials |
Type |
A1 Journal article |
| |
Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
96 |
Issue |
8 |
Pages |
085135 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-)local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes. |
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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 |
000408342600003 |
Publication Date |
2017-08-24 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
6 |
Open Access |
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Notes |
Fonds Wetenschappelijk Onderzoek, G. 0224.14N ; U.S. Department of Energy, DE-FG02-07ER46352 DE-AC02-05CH11231 DE-SC0012575 ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @c:irua:145703 |
Serial |
4703 |
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Author |
Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V. |
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Title |
Effects of spatially engineered Dzyaloshinskii-Moriya interaction in ferromagnetic films |
Type |
A1 Journal article |
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Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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Volume |
95 |
Issue |
95 |
Pages |
144401 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
The Dzyaloshinskii-Moriya interaction (DMI) is a chiral interaction that favors formation of domain walls. Recent experiments and ab initio calculations show that there are multiple ways to modify the strength of the interfacially induced DMI in thin ferromagnetic films with perpendicular magnetic anisotropy. In this paper we reveal theoretically the effects of spatially varied DMI on the magnetic state in thin films. In such heterochiral 2D structures we report several emergent phenomena, ranging from the equilibrium spin canting at the interface between regions with different DMI, over particularly strong confinement of domain walls and skyrmions within high-DMI tracks, to advanced applications such as domain tailoring nearly at will, design of magnonic waveguides, and much improved skyrmion racetrack memory. |
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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 |
000399382100003 |
Publication Date |
2017-04-03 |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
3.836 |
Times cited |
60 |
Open Access |
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Notes |
Fonds Wetenschappelijk Onderzoek, G098917N ; |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @ c:irua:141917 |
Serial |
4534 |
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Author |
Chaves, A.; Covaci, L.; Peeters, F.M.; Milošević, M.V. |
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Title |
Topologically protected moiré exciton at a twist-boundary in a van der Waals heterostructure |
Type |
A1 Journal article |
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Year |
2022 |
Publication |
2D materials |
Abbreviated Journal |
2D Mater |
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Volume |
9 |
Issue |
2 |
Pages |
025012 |
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Keywords |
A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) |
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Abstract |
A twin boundary in one of the layers of a twisted van der Waals heterostructure separates regions with near opposite inter-layer twist angles. In a MoS<sub>2</sub>/WSe<sub>2</sub>bilayer, the regions with<inline-formula><tex-math><?CDATA $Rh^h$?></tex-math><math overflow=“scroll”><msubsup><mi>R</mi><mi>h</mi><mi>h</mi></msubsup></math><inline-graphic href=“tdmac529dieqn1.gif” type=“simple” /></inline-formula>and<inline-formula><tex-math><?CDATA $Rh^X$?></tex-math><math overflow=“scroll”><msubsup><mi>R</mi><mi>h</mi><mi>X</mi></msubsup></math><inline-graphic href=“tdmac529dieqn2.gif” type=“simple” /></inline-formula>stacking registry that defined the sub-lattices of the moiré honeycomb pattern would be mirror-reflected across such a twist boundary. In that case, we demonstrate that topologically protected chiral moiré exciton states are confined at the twist boundary. These are one-dimensional and uni-directional excitons with opposite velocities for excitons composed by electronic states with opposite valley/spin character, enabling intrinsic, guided, and far reaching valley-polarized exciton currents. |
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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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Language |
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Wos |
000760518100001 |
Publication Date |
2022-04-01 |
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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 |
2053-1583 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
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Impact Factor |
5.5 |
Times cited |
|
Open Access |
OpenAccess |
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Notes |
Fonds Wetenschappelijk Onderzoek; Conselho Nacional de Desenvolvimento Científico e Tecnológico, PQ ; |
Approved |
Most recent IF: 5.5 |
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Call Number |
CMT @ cmt @c:irua:187124 |
Serial |
7046 |
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Author |
Bekaert, J.; Vercauteren, S.; Aperis, A.; Komendová, L.; Prozorov, R.; Partoens, B.; Milošević, M.V. |
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Title |
Anisotropic type-I superconductivity and anomalous superfluid density in OsB2 |
Type |
A1 Journal article |
| |
Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
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| |
Volume |
94 |
Issue |
94 |
Pages |
144506 |
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Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
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Abstract |
We present a microscopic study of superconductivity in OsB2 , and discuss the origin and characteristic length
scales of the superconducting state. From first-principles we show that OsB2 is characterized by three different
Fermi sheets, and we prove that this fermiology complies with recent quantum-oscillation experiments. Using the
found microscopic properties, and experimental data from the literature, we employ Ginzburg-Landau relations
to reveal that OsB2 is a distinctly type-I superconductor with a very low Ginzburg-Landau parameter κ—a rare
property among compound materials. We show that the found coherence length and penetration depth corroborate
the measured thermodynamic critical field. Moreover, our calculation of the superconducting gap structure using
anisotropic Eliashberg theory and ab initio calculated electron-phonon interaction as input reveals a single but
anisotropic gap. The calculated gap spectrum is shown to give an excellent account for the unconventional
behavior of the superfluid density of OsB2 measured in experiments as a function of temperature. This reveals
that gap anisotropy can explain such behavior, observed in several compounds, which was previously attributed
solely to a two-gap nature of superconductivity. |
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Address |
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Corporate Author |
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Thesis |
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Publisher |
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Place of Publication |
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Editor |
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Language |
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Wos |
000385622500009 |
Publication Date |
2016-10-12 |
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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 |
2469-9950 |
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 |
Fonds Wetenschappelijk Onderzoek; European Cooperation in Science and Technology, MP1201 ; Vetenskapsrådet; |
Approved |
Most recent IF: 3.836 |
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Call Number |
CMT @ cmt @ c:irua:139020 |
Serial |
4338 |
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| Permanent link to this record |
