| Records |
| Author |
Zhang, H.Y.; Xiao, Y.M.; N. Li, Q.; Ding, L.; Van Duppen, B.; Xu, W.; Peeters, F.M. |
Title  |
Anisotropic and tunable optical conductivity of a two-dimensional semi-Dirac system in the presence of elliptically polarized radiation |
Type |
A1 Journal article |
| Year |
2022 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
105 |
Issue |
11 |
Pages |
115423-115429 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We investigate the effect of ellipticity ratio of the polarized radiation field on optoelectronic properties of a two-dimensional (2D) semi-Dirac (SD) system. The optical conductivity is calculated within the energy balance equation approach derived from the semiclassical Boltzmann equation. We find that there exists the anisotropic optical absorption induced via both the intra-and interband electronic transition channels in the perpendicular xx and yy directions. Furthermore, we examine the effects of the ellipticity ratio, the temperature, the carrier density, and the band-gap parameter on the optical conductivity of the 2D SD system placed in transverse and vertical directions, respectively. It is shown that the ellipticity ratio, temperature, carrier density, and band-gap parameter can play the important roles in tuning the strength, peak position, and shape of the optical conductivity spectrum. The results obtained from this study indicate that the 2D SD system can be a promising anisotropic and tunable optical and optoelectronic material for applications in innovative 2D optical and optoelectronic devices, which are active in the infrared and terahertz bandwidths. |
| 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 |
000802810700002 |
Publication Date |
2022-03-22 |
| 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 |
| Impact Factor |
3.7 |
Times cited |
3 |
Open Access |
OpenAccess |
| Notes |
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Approved |
Most recent IF: 3.7 |
| Call Number |
UA @ admin @ c:irua:188660 |
Serial |
7125 |
| Permanent link to this record |
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| Author |
Cavalcante, L.S.; Chaves, A.; da Costa, D.R.; Farias, G.A.; Peeters, F.M. |
| Title |
All-strain based valley filter in graphene nanoribbons using snake states |
Type |
A1 Journal article |
| Year |
2016 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
94 |
Issue |
7 |
Pages |
075432 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
A pseudomagnetic field kink can be realized along a graphene nanoribbon using strain engineering. Electron transport along this kink is governed by snake states that are characterized by a single propagation direction. Those pseudomagnetic fields point towards opposite directions in the K and K' valleys, leading to valley polarized snake states. In a graphene nanoribbon with armchair edges this effect results in a valley filter that is based only on strain engineering. We discuss how to maximize this valley filtering by adjusting the parameters that define the stress distribution along the graphene ribbon. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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| Language |
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Wos |
000381889300002 |
Publication Date |
2016-08-23 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
29 |
Open Access |
|
| Notes |
; Discussions with R. Grassi are gratefully acknowledged. This work was supported by the Brazilian Council for Research (CNPq), under the PRONEX/FUNCAP and Science Without Borders (SWB) programs, CAPES, the Lemann Foundation, and the Flemish Science Foundation (FWO-Vl). ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:144667 |
Serial |
4639 |
| Permanent link to this record |
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| Author |
Li, L.L.; Moldovan, D.; Vasilopoulos, P.; Peeters, F.M. |
| Title |
Aharonov-Bohm oscillations in phosphorene quantum rings |
Type |
A1 Journal article |
| Year |
2017 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
95 |
Issue |
20 |
Pages |
205426 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The Aharonov-Bohm (AB) effect in square phosphorene quantum rings, with armchair and zigzag edges, is investigated using the tight-binding method. The energy spectra and wave functions of such rings, obtained as a function of the magnetic flux Phi threading the ring, are strongly influenced by the ringwidthW, an in-plane electric field E-p, and a side-gating potential V-g. Compared to a square dot, the ring shows an enhanced confinement due to its inner edges and an interedge coupling along the zigzag direction, both of which strongly affect the energy spectrum and the wave functions. The energy spectrum that is gapped consists of a regular part, of conduction (valence) band states, that shows the usual AB oscillations in the higher-(lower-) energy region, and of edge states, in the gap, that exhibit no AB oscillations. As the width W decreases, the AB oscillations become more distinct and regular and their period is close to Phi(0)/2, where the flux quantum Phi(0) = h/e is the period of an ideal circular ring (W -> 0). Both the electric field E-p and the side-gating potential V-g reduce the amplitude of the AB oscillations. The amplitude can be effectively tuned by E-p or V-g and exhibits an anisotropic behavior for different field directions or side-gating configurations. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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| Language |
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Wos |
000402003700010 |
Publication Date |
2017-05-23 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
16 |
Open Access |
|
| Notes |
; This work was financially supported by the Chinese Academy of Sciences, the Flemish Science Foundation (FWO-V1), and by the Canadian NSERC Grant No. OGP0121756 (P.V.). ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:144267 |
Serial |
4638 |
| Permanent link to this record |
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| Author |
Bekaert, J.; Aperis, A.; Partoens, B.; Oppeneer, P.M.; Milošević, M.V. |
| Title |
Advanced first-principles theory of superconductivity including both lattice vibrations and spin fluctuations : the case of FeB4 |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
97 |
Issue |
1 |
Pages |
014503 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
<script type='text/javascript'>document.write(unpmarked('We present an advanced method to study spin fluctuations in superconductors quantitatively and entirely from first principles. This method can be generally applied to materials where electron-phonon coupling and spin fluctuations coexist. We employ it here to examine the recently synthesized superconductor iron tetraboride (FeB4) with experimental T-c similar to 2.4 K [H. Gou et al., Phys. Rev. Lett, 111, 157002 (2013)]. We prove that FeB4 is particularly prone to ferromagnetic spin fluctuations due to the presence of iron, resulting in a large Stoner interaction strength, I = 1.5 eV, as calculated from first principles. The other important factor is its Fermi surface that consists of three separate sheets, among which two are nested ellipsoids. The resulting susceptibility has a ferromagnetic peak around q = 0, from which we calculated the repulsive interaction between Cooper pair electrons using the random phase approximation. Subsequently, we combined the electron-phonon interaction calculated from first principles with the spin fluctuation interaction in fully anisotropic Eliashberg theory calculations. We show that the resulting superconducting gap spectrum is conventional, yet very strongly depleted due to coupling to the spin fluctuations. The critical temperature decreases from T-c = 41 K, if they are not taken into account, to T-c = 1.7 K, in good agreement with the experimental value.')); |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
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| Language |
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Wos |
000419229100004 |
Publication Date |
2018-01-04 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.836 |
Times cited |
23 |
Open Access |
|
| Notes |
; This work was supported by TOPBOF-UAntwerp, Research Foundation Flanders (FWO), the Swedish Research Council (VR), and the Rontgen-Angstrom Cluster. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation Flanders (FWO) and the Flemish Government-department EWI. Anisotropic Eliashberg theory calculations were supported through the Swedish National Infrastructure for Computing (SNIC). ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:148447UA @ admin @ c:irua:148447 |
Serial |
4866 |
| Permanent link to this record |
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| Author |
Torre, I.; de Castro, L.V.; Van Duppen, B.; Barcons Ruiz, D.; Peeters, F.M.; Koppens, F.H.L.; Polini, M. |
| Title |
Acoustic plasmons at the crossover between the collisionless and hydrodynamic regimes in two-dimensional electron liquids |
Type |
A1 Journal article |
| Year |
2019 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
99 |
Issue |
14 |
Pages |
144307 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
Hydrodynamic flow in two-dimensional electron systems has so far been probed only by dc transport and scanning gate microscopy measurements. In this work we discuss theoretically signatures of the hydrodynamic regime in near-field optical microscopy. We analyze the dispersion of acoustic plasmon modes in two-dimensional electron liquids using a nonlocal conductivity that takes into account the effects of (momentumconserving) electron-electron collisions, (momentum-relaxing) electron-phonon and electron-impurity collisions, and many-body interactions beyond the celebrated random phase approximation. We derive the dispersion and, most importantly, the damping of acoustic plasmon modes and their coupling to a near-field probe, identifying key experimental signatures of the crossover between collisionless and hydrodynamic regimes. |
| 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 |
000465160000003 |
Publication Date |
2019-04-18 |
| 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 |
| Impact Factor |
3.836 |
Times cited |
14 |
Open Access |
|
| Notes |
; This work has been sponsored by the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 785219 “Graphene Core2” and via the European Research Council (ERC) Grant Agreement No. 786285. B.V.D. is supported by a post-doctoral fellowship of the Flemish Science Foundation (FWO-Vl). F.H.L.K. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through the “ Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0522), support by Fundacio Cellex Barcelona, Generalitat de Catalunya through the CERCA program, and the Mineco grant Plan Nacional (FIS2016-81044-P) and the Agency for Management of University and Research Grants (AGAUR) 2017 SGR 1656. F.M.P. and L.V.d.C. were supported by the Methusalem Program of the Flemish Government. We thank Niels Hesp and Hanan Hertzig Sheinfux for useful discussions. ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:159333 |
Serial |
5193 |
| Permanent link to this record |
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| Author |
Sabani, D.; Bacaksiz, C.; Milošević, M.V. |
| Title |
Ab initio methodology for magnetic exchange parameters: Generic four-state energy mapping onto a Heisenberg spin Hamiltonian |
Type |
A1 Journal article |
| Year |
2020 |
Publication |
Physical Review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
102 |
Issue |
1 |
Pages |
014457-14458 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
The recent development in the field of two-dimensional magnetic materials urges reliable theoretical methodology for determination of magnetic properties. Among the available methods, ab initio four-state energy mapping based on density functional theory stands out as a powerful technique to calculate the magnetic exchange interaction in the Heisenberg spin model. Although the required formulas were explained in earlier works, the considered Hamiltonian in those studies always corresponded to the specific case that the off-diagonal part of J matrix is antisymmetric, which may be misleading in other cases. Therefore, using the most general form of the Heisenberg spin Hamiltonian, we here derive the generic formulas. With a proper choice of four different magnetic states, a single formula governs all elements of the exchange interaction matrix for any considered pair of spin sites. |
| 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 |
000554409500002 |
Publication Date |
2020-07-31 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
2469-9969; 2469-9950 |
ISBN |
|
Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.7 |
Times cited |
13 |
Open Access |
|
| Notes |
; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen) and the Special Research Funds of the University of Antwerp (TOPBOF). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation-Flanders (FWO-Vlaanderen) and the Flemish Government, Department EWI. ; |
Approved |
Most recent IF: 3.7; 2020 IF: 3.836 |
| Call Number |
UA @ admin @ c:irua:171203 |
Serial |
6448 |
| Permanent link to this record |
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| |
| Author |
Torun, E.; Sahin, H.; Chaves, A.; Wirtz, L.; Peeters, F.M. |
| Title |
Ab initio and semiempirical modeling of excitons and trions in monolayer TiS3 |
Type |
A1 Journal article |
| Year |
2018 |
Publication |
Physical review B |
Abbreviated Journal |
Phys Rev B |
| Volume |
98 |
Issue |
7 |
Pages |
075419 |
| Keywords |
A1 Journal article; Condensed Matter Theory (CMT) |
| Abstract |
We explore the electronic and the optical properties of monolayer TiS3, which shows in-plane anisotropy and is composed of a chain-like structure along one of the lattice directions. Together with its robust direct band gap, which changes very slightly with stacking order and with the thickness of the sample, the anisotropic physical properties of TiS3 make the material very attractive for various device applications. In this study, we present a detailed investigation on the effect of the crystal anisotropy on the excitons and the trions of the TiS3 monolayer. We use many-body perturbation theory to calculate the absorption spectrum of anisotropic TiS3 monolayer by solving the Bethe-Salpeter equation. In parallel, we implement and use a Wannier-Mott model for the excitons that takes into account the anisotropic effective masses and Coulomb screening, which are obtained from ab initio calculations. This model is then extended for the investigation of trion states of monolayer TiS3. Our calculations indicate that the absorption spectrum of monolayer TiS3 drastically depends on the polarization of the incoming light, which excites different excitons with distinct binding energies. In addition, the binding energies of positively and the negatively charged trions are observed to be distinct and they exhibit an anisotropic probability density distribution. |
| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
American Physical Society |
Place of Publication |
New York, N.Y |
Editor |
|
| Language |
|
Wos |
000442342100002 |
Publication Date |
2018-08-21 |
| Series Editor |
|
Series Title |
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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 |
3.836 |
Times cited |
10 |
Open Access |
|
| Notes |
; This work was supported by the Flemish Science Foundation (FWO-Vl) and the FLAG-ERA project TRANS-2D-TMD. H.S. acknowledges financial support from TUBITAK under Project No. 117F095. A.C. acknowledges support from the Brazilian Research Council (CNPq), through the PRONEX/FUNCAP and Science Without Borders programs, and from the Lemann Foundation. E.T. and L.W. acknowledge support from the National Research Fund, Luxembourg (IN-TER/ANR/13/20/NANOTMD). ; |
Approved |
Most recent IF: 3.836 |
| Call Number |
UA @ lucian @ c:irua:153721UA @ admin @ c:irua:153721 |
Serial |
5076 |
| Permanent link to this record |
