| Home | << 1 2 3 4 5 6 7 8 >> |
|
| Records | |||||
|---|---|---|---|---|---|
| Author | Lima, I.L.C.; Milošević, M.V.; Peeters, F.M.; Chaves, A. | ||||
| Title | Tuning of exciton type by environmental screening | Type | A1 Journal article | ||
| Year | 2023 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 108 | Issue | 11 | Pages | 115303-115308 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We theoretically investigate the binding energy and electron-hole (e-h) overlap of excitonic states confined at the interface between two-dimensional materials with type-II band alignment, i.e., with lowest conduction and highest valence band edges placed in different materials, arranged in a side-by-side planar heterostructure. We propose a variational procedure within the effective mass approximation to calculate the exciton ground state and apply our model to a monolayer MoS2/WS2 heterostructure. The role of nonabrupt interfaces between the materials is accounted for in our model by assuming a WxMo1-xS2 alloy around the interfacial region. Our results demonstrate that (i) interface-bound excitons are energetically favorable only for small interface thickness and/or for systems under high dielectric screening by the materials surrounding the monolayer, and that (ii) the interface exciton binding energy and its e-h overlap are controllable by the interface width and dielectric environment. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001077758300002 | Publication Date | 2023-09-08 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | 3.7 | Times cited | Open Access  |
||
| Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:200356 | Serial | 9110 | ||
| Permanent link to this record | |||||
| Author | Wang, J.; Zhao, W.-S.; Hu, Y.; Filho, R.N.C.; Peeters, F.M. | ||||
| Title | Charged vacancy in graphene : interplay between Landau levels and atomic collapse resonances | Type | A1 Journal article | ||
| Year | 2024 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 109 | Issue | 10 | Pages | 104103-104106 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The interplay between a magnetic field and the Coulomb potential from a charged vacancy on the electron states in graphene is investigated within the tight-binding model. The Coulomb potential removes locally Landau level degeneracy, while the vacancy introduces a satellite level next to the normal Landau level. These satellite levels are found throughout the positive-energy region, but in the negative-energy region, they turn into atomic collapse resonances. Crossings between Landau levels with different angular quantum number m are found. Unlike the point impurity system in which an anticrossing occurs between Landau levels of the same m, in this work anticrossing is found between the normal Landau level and the vacancy-induced level. The atomic collapse resonance hybridizes with the Landau levels. The charge at which the lowest Landau level m = -1, N = 1 crosses E = 0 increases with enhancing magnetic field. A Landau level scaling anomaly occurs when the charge is larger than the critical charge beta 0.6 and this critical charge is independent of the magnetic field. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001199561900008 | Publication Date | 2024-03-04 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | Times cited | Open Access |
|||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:205508 | Serial | 9137 | ||
| Permanent link to this record | |||||
| Author | Pascucci, F.; Conti, S.; Perali, A.; Tempère, J.; Neilson, D. | ||||
| Title | Effects of intralayer correlations on electron-hole double-layer superfluidity | Type | A1 Journal article | ||
| Year | 2024 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 109 | Issue | 9 | Pages | 094512-94515 |
| Keywords | A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT) | ||||
| Abstract | We investigate the intralayer correlations acting within the layers in a superfluid system of electron -hole spatially separated layers. In this system, superfluidity is predicted to be almost exclusively confined to the Bose-Einstein condensate (BEC) and crossover regimes where the electron -hole pairs are well localized. In this case, Hartree-Fock is an excellent approximation for the intralayer correlations. We find in the BEC regime that the effect of the intralayer correlations on superfluid properties is negligible but in the BCS-BEC crossover regime the superfluid gap is significantly weakened by the intralayer correlations. This is caused by the intralayer correlations boosting the number of low -energy particle -hole excitations that drive the screening. We further find that the intralayer correlations suppress the predicted phenomenon in which the average pair size passes through a minimum as the crossover regime is traversed. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001199662600001 | Publication Date | 2024-03-18 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | Times cited | Open Access |
|||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:205476 | Serial | 9145 | ||
| Permanent link to this record | |||||
| Author | Moura, V.N.; Chaves, A.; Peeters, F.M.; Milošević, M.V. | ||||
| Title | McMillan-Ginzburg-Landau theory of singularities and discommensurations in charge density wave states of transition metal dichalcogenides | Type | A1 Journal article | ||
| Year | 2024 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 109 | Issue | 9 | Pages | 094507-94511 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The McMillan-Ginzburg-Landau (MGL) model for charge density waves (CDW) is employed in a systematic phenomenological study of the different phases that have been probed in recent experiments involving transition metal dichalcogenides. We implemented an efficient imaginary time evolution method to solve the MGL equations, which enabled us to investigate the role of different coupling parameters on the CDW patterns and to perform calculations with different energy functionals that lead to several experimentally observed singularities in the CDW phase profiles. In particular, by choosing the appropriate energy functionals, we were able to obtain phases that go beyond the well-known periodic phase slips (discommensurations), exhibiting also topological defects (i.e., vortex-antivortex pairs), domain walls where the CDW order parameter is suppressed, and even CDW with broken rotational symmetry. Finally, we briefly discuss the effect of these different CDW phases on the profile and critical temperature of the competing superconducting state. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001199651500001 | Publication Date | 2024-03-11 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | Times cited | Open Access |
|||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:205491 | Serial | 9158 | ||
| Permanent link to this record | |||||
| Author | Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. | ||||
| Title | Tailoring weak and metallic phases in a strong topological insulator by strain and disorder : conductance fluctuations signatures | Type | A1 Journal article | ||
| Year | 2024 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 109 | Issue | 4 | Pages | 045129-7 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Transport measurements are readily used to probe different phases in disordered topological insulators (TIs), where determining topological invariants explicitly is challenging. On that note, universal conductance fluctuations (UCF) theory asserts the conductance G for an ensemble has a Gaussian distribution, and that standard deviation 8G depends solely on the symmetries and dimensions of the system. Using a real-space tight -binding Hamiltonian on a system with Anderson disorder, we explore conductance fluctuations in a thin Bi2Se3 film and demonstrate the agreement of their behavior with UCF hypotheses. We further show that magnetic field applied out-of-plane breaks the time -reversal symmetry and transforms the system's Wigner-Dyson class from root symplectic to unitary, increasing 8G by 2. Finally, we reveal that while Bi2Se3 is a strong TI, weak TI and metallic phases can be stabilized in presence of strain and disorder, and detected by monitoring the conductance fluctuations. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001173938400008 | Publication Date | 2024-01-16 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9969; 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | Times cited | Open Access |
|||
| Notes | Approved | no | |||
| Call Number | UA @ admin @ c:irua:204765 | Serial | 9177 | ||
| Permanent link to this record | |||||
| Author | Stosic, D.; Mulkers, J.; Van Waeyenberge, B.; Ludermir, T.B.; Milošević, M.V. | ||||
| Title | Paths to collapse for isolated skyrmions in few-monolayer ferromagnetic films | Type | A1 Journal article | ||
| Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 95 | Issue | 21 | Pages | 214418 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Magnetic skyrmions are topological spin configurations in materials with chiral Dzyaloshinskii-Moriya interaction (DMI), that are potentially useful for storing or processing information. To date, DMI has been found in few bulk materials, but can also be induced in atomically thin magnetic films in contact with surfaces with large spin-orbit interactions. Recent experiments have reported that isolated magnetic skyrmions can be stabilized even near room temperature in few-atom-thick magnetic layers sandwiched between materials that provide asymmetric spin-orbit coupling. Here we present the minimum-energy path analysis of three distinct mechanisms for the skyrmion collapse, based on ab initio input and the performed atomic-spin simulations. We focus on the stability of a skyrmion in three atomic layers of Co, either epitaxial on the Pt(111) surface or within a hybrid multilayer where DMI nontrivially varies per monolayer due to competition between different symmetry breaking from two sides of the Co film. In laterally finite systems, their constrained geometry causes poor thermal stability of the skyrmion toward collapse at the boundary, which we show to be resolved by designing the high-DMI structure within an extended film with lower or no DMI. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000404015500001 | Publication Date | 2017-06-23 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 48 | Open Access |
|
| Notes | This work was supported by the Research Foundation, Flanders (FWO-Vlaanderen) and Brazilian agency CNPq (Grants No. 442668/2014-7 and No. 140840/2016-8). | Approved | Most recent IF: 3.836 | ||
| Call Number | CMT @ cmt @c:irua:144865 | Serial | 4704 | ||
| Permanent link to this record | |||||
| Author | Callewaert, V.; Saniz, R.; Barbiellini, B.; Bansil, A.; Partoens, B. | ||||
| Title | Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials | Type | A1 Journal article | ||
| Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 96 | Issue | 8 | Pages | 085135 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-)local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000408342600003 | Publication Date | 2017-08-24 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 6 | Open Access |
|
| Notes | Fonds Wetenschappelijk Onderzoek, G. 0224.14N ; U.S. Department of Energy, DE-FG02-07ER46352 DE-AC02-05CH11231 DE-SC0012575 ; | Approved | Most recent IF: 3.836 | ||
| Call Number | CMT @ cmt @c:irua:145703 | Serial | 4703 | ||
| Permanent link to this record | |||||
| Author | da Costa, D.R.; Zarenia, M.; Chaves, A.; Farias, G.A.; Peeters, F.M. | ||||
| Title | Magnetic field dependence of energy levels in biased bilayer graphene quantum dots | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 93 | Issue | 93 | Pages | 085401 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Using the tight-binding approach, we study the influence of a perpendicular magnetic field on the energy levels of hexagonal, triangular, and circular bilayer graphene (BLG) quantum dots (QDs) with zigzag and armchair edges. We obtain the energy levels for AB (Bernal)-stacked BLG QDs in both the absence and the presence of a perpendicular electric field (i.e., biased BLG QDs). We find different regions in the spectrum of biased QDs with respect to the crossing point between the lowest-electron and -hole Landau levels of a biased BLG sheet. Those different regions correspond to electron states that are localized at the center, edge, or corner of the BLG QD. Quantum Hall corner states are found to be absent in circular BLG QDs. The spatial symmetry of the carrier density distribution is related to the symmetry of the confinement potential, the position of zigzag edges, and the presence or absence of interlayer inversion symmetry. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000369402400008 | Publication Date | 2016-02-01 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 22 | Open Access |
|
| Notes | ; This work was financially supported by CNPq, under Contract No. NanoBioEstruturas 555183/2005-0, PRONEX/FUNCAP, CAPES Foundation under the Process No. BEX 7178/13-1, the Flemish Science Foundation (FWO-Vl), the Bilateral programme between CNPq and FWO-Vl, and the Brazilian Program Science Without Borders (CsF). ; | Approved | Most recent IF: 3.836 | ||
| Call Number | c:irua:131623 | Serial | 4038 | ||
| Permanent link to this record | |||||
| Author | Covaci, L.; Marsiglio, F. | ||||
| Title | Proximity effect and Josephson current in clean strong/weak/strong superconducting trilayers | Type | A1 Journal article | ||
| Year | 2006 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 73 | Issue | 1 | Pages | 014503 |
| Keywords | A1 Journal article | ||||
| Abstract | Recent measurements of the Josephson critical current through LSCO/LCO/LSCO thin films showed an unusually large proximity effect. Using the Bogoliubov-de Gennes equations for a tight-binding Hamiltonian we describe the proximity effect in weak links between a superconductor with critical temperature T-c and one with critical temperature T-c('), where T-c > T-c('). The weak link (N-') is therefore a superconductor above its own critical temperature and the superconducting regions are considered to have either s-wave or d-wave symmetry. We note that the proximity effect is enhanced due to the presence of superconducting correlations in the weak link. The dc Josephson current is calculated, and we obtain a nonzero value for temperatures greater than T-c(') for sizes of the weak links that can be almost an order of magnitude greater than the conventional coherence length. Considering pockets of superconductivity in the N-' layer, we show that this can lead to an even larger effect on the Josephson critical current by effectively shortening the weak link. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000235009000103 | Publication Date | 2006-01-03 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | 31 | Open Access |
|
| Notes | Approved | Most recent IF: 3.836; 2006 IF: 3.107 | |||
| Call Number | UA @ lucian @ | Serial | 4427 | ||
| Permanent link to this record | |||||
| Author | Bekaert, J.; Vercauteren, S.; Aperis, A.; Komendová, L.; Prozorov, R.; Partoens, B.; Milošević, M.V. | ||||
| 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 |
| Volume | 94 | Issue | 94 | Pages | 144506 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| 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. |
||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000385622500009 | Publication Date | 2016-10-12 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 19 | Open Access |
|
| Notes | Fonds Wetenschappelijk Onderzoek; European Cooperation in Science and Technology, MP1201 ; Vetenskapsrådet; | Approved | Most recent IF: 3.836 | ||
| Call Number | CMT @ cmt @ c:irua:139020 | Serial | 4338 | ||
| Permanent link to this record | |||||
| Author | Doğan, F.; Covaci, L.; Kim, W.; Marsiglio, F. | ||||
| Title | Emerging nonequilibrium bound state in spin-current–local-spin scattering | Type | A1 Journal article | ||
| Year | 2009 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 80 | Issue | 10 | Pages | 104434 |
| Keywords | A1 Journal article | ||||
| Abstract | Magnetization reversal is a well-studied problem with obvious applicability in computer hard drives. One can accomplish a magnetization reversal in at least one of two ways: application of a magnetic field or through a spin current. The latter is more amenable to a fully quantum-mechanical analysis. We formulate and solve the problem whereby a spin current interacts with a ferromagnetic Heisenberg spin chain, to eventually reverse the magnetization of the chain. Spin flips are accomplished through both elastic and inelastic scattering. A consequence of the inelastic-scattering channel, when it is no longer energetically possible, is the occurrence of a nonequilibrium bound state, which is an emergent property of the coupled local plus itinerant spin system. For certain definite parameter values the itinerant spin lingers near the local spins for some time, before eventually leaking out as an outwardly diffusing state. This phenomenon results in spin-flip dynamics and filtering properties for this type of system. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000270383100077 | Publication Date | 2009-09-25 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | Open Access |
||
| Notes | Approved | Most recent IF: 3.836; 2009 IF: 3.475 | |||
| Call Number | UA @ lucian @ | Serial | 4436 | ||
| Permanent link to this record | |||||
| Author | Kim, W.; Covaci, L.; Marsiglio, F. | ||||
| Title | Impurity scattering of wave packets on a lattice | Type | A1 Journal article | ||
| Year | 2006 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 74 | Issue | 20 | Pages | 205120 |
| Keywords | A1 Journal article | ||||
| Abstract | Quantum transport in a lattice is distinct from its counterpart in continuum media. Even a free wave packet travels differently in a lattice than in the continuum. We describe quantum scattering in a one-dimensional lattice and illustrate characteristics of quantum transport such as resonant transmission. In particular we examine the transport characteristics of a random trimer model. We demonstrate the real-time propagation of a wave packet and its phase shift due to impurity configurations. Spin-flip scattering is also taken into account in a spin-chain system. We show how individual spins in the chain evolve as a result of a spin-flip interaction between an incoming electron and a spin chain. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000242409400030 | Publication Date | 2006-11-27 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | 14 | Open Access |
|
| Notes | Approved | Most recent IF: 3.836; 2006 IF: 3.107 | |||
| Call Number | UA @ lucian @ | Serial | 4428 | ||
| Permanent link to this record | |||||
| Author | Kim, W.; Covaci, L.; Marsiglio, F. | ||||
| Title | Hidden symmetries of electronic transport in a disordered one-dimensional lattice | Type | A1 Journal article | ||
| Year | 2006 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 73 | Issue | 19 | Pages | 195109 |
| Keywords | A1 Journal article | ||||
| Abstract | Correlated, or extended, impurities play an important role in the transport properties of dirty metals. Here, we examine, in the framework of a tight-binding lattice, the transmission of a single electron through an array of correlated impurities. In particular we show that particles transmit through an impurity array in identical fashion, regardless of the direction of traversal. The demonstration of this fact is straightforward in the continuum limit, but requires a detailed proof for the discrete lattice. We also briefly demonstrate and discuss the time evolution of these scattering states, to delineate regions (in time and space) where the aforementioned symmetry is violated. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000237950400042 | Publication Date | 2006-05-11 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1098-0121 | ISBN | Additional Links | ||
| Impact Factor | 3.836 | Times cited | 5 | Open Access |
|
| Notes | Approved | Most recent IF: 3.836; 2006 IF: 3.107 | |||
| Call Number | UA @ lucian @ | Serial | 4429 | ||
| Permanent link to this record | |||||
| Author | Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V. | ||||
| Title | Effects of spatially engineered Dzyaloshinskii-Moriya interaction in ferromagnetic films | Type | A1 Journal article | ||
| Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 95 | Issue | 95 | Pages | 144401 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| 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. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000399382100003 | Publication Date | 2017-04-03 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 60 | Open Access |
|
| Notes | Fonds Wetenschappelijk Onderzoek, G098917N ; | Approved | Most recent IF: 3.836 | ||
| Call Number | CMT @ cmt @ c:irua:141917 | Serial | 4534 | ||
| Permanent link to this record | |||||
| Author | N. Gauquelin, E. Benckiser, M. K. Kinyanjui, M. Wu, Y. Lu, G. Christiani, G. Logvenov, H.-U. Habermeier, U. Kaiser, B. Keimer, and G. A. Botton | ||||
| Title | Atomically resolved EELS mapping of the interfacial structure of epitaxially strained LaNiO3/LaAlO3 superlattices | Type | A1 Journal Article | ||
| Year | 2014 | Publication | Physical Review B | Abbreviated Journal | |
| Volume | 90 | Issue | Pages | 195140 | |
| Keywords | A1 Journal Article; Electron Microscopy for Materials Science (EMAT) ; | ||||
| Abstract | The interfacial atomic structure of a metallic LaNiO3/LaAlO3 superlattice grown on a LaSrAlO4 substrate was investigated using a combination of atomically resolved electron energy loss spectroscopy (EELS) at the Al K, Al L2,3, Sr L2,3, Ni L2,3, La M4,5, and O K edges as well as hybridization mapping of selected features of the O K-edge fine structure.We observe an additional La1−xSrxAl1−yNiyO3 layer at the substrate-superlattice interface, possibly linked to diffusion of Al and Sr into the growing film or a surface reconstruction due to Sr segregation. The roughness of the LaNiO3/LaAlO3 interfaces is found to be on average around one pseudocubic unit cell. The O K-edge EELS spectra revealed reduced spectral weight of the prepeak derived from Ni-O hybridized states in the LaNiO3 layers. We rule out oxygen nonstoichiometry of the LaNiO3 layers and discuss changes in the Ni-O hybridization due to heterostructuring as possible origin. |
||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000345467000003 | Publication Date | 2014-11-20 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 17 | Open Access |
||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4544 | ||
| Permanent link to this record | |||||
| Author | Han, F.W.; Xu, W.; Li, L.L.; Zhang, C.; Dong, H.M.; Peeters, F.M. | ||||
| Title | Electronic and transport properties of n-type monolayer black phosphorus at low temperatures | Type | A1 Journal article | ||
| Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 95 | Issue | 95 | Pages | 115436 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We present a detailed theoretical study of the electronic and transport properties of monolayer black phosphorus (BP). This study is motivated by recent experimental activities in investigating n-type few-layer BP systems. The electron density of states, the screening length, and the low-temperature electron mobility are calculated for monolayer BP (MLBP). In particular, the electron transport mobilities along the armchair and zigzag directions are examined on the basis of the momentum-balance equation derived from a semiclassical Boltzmann equation. The anisotropic electron mobilities in MLBP along different directions are demonstrated where the electron-impurity scattering is considered. Furthermore, we compare the results obtained from two electronic band structures of MLBP and find that the simplified model can describe quite rightly the electronic and transport properties of MLBP. This study is relevant to the application of few-layer BP based electronic systems as advanced electronic devices. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000399140700012 | Publication Date | 2017-03-27 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 12 | Open Access |
|
| Notes | National Natural Science Foundation of China, 11574319 11304316 11304317 11604380 ; Ministry of Science and Technology of the People's Republic of China, 2011YQ130018 ; Chinese Academy of Sciences; | Approved | Most recent IF: 3.836 | ||
| Call Number | CMT @ cmt @ c:irua:142431 | Serial | 4564 | ||
| Permanent link to this record | |||||
| Author | Vagov, A.; Shanenko, A.A.; Milošević, M.V.; Axt, V.M.; Vinokur, V.M.; Aguiar, J.A.; Peeters, F.M. | ||||
| 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 |
| Volume | 93 | Issue | 93 | Pages | 174503 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | |||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000375527500001 | Publication Date | 2016-05-06 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 37 | Open Access |
|
| 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 | ||
| Call Number | CMT @ cmt @ c:irua:141732 | Serial | 4480 | ||
| Permanent link to this record | |||||
| Author | Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V. | ||||
| Title | Tunable Snell's law for spin waves in heterochiral magnetic films | Type | A1 Journal article | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 97 | Issue | 10 | Pages | 104422 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Thin ferromagnetic films with an interfacially induced DMI exhibit nontrivial asymmetric dispersion relations that lead to unique and useful magnonic properties. Here we derive an analytical expression for the magnon propagation angle within the micromagnetic framework and show how the dispersion relation can be approximated with a comprehensible geometrical interpretation in the k space of the propagation of spin waves. We further explore the refraction of spin waves at DMI interfaces in heterochiral magnetic films, after deriving a generalized Snell's law tunable by an in-plane magnetic field, that yields analytical expressions for critical incident angles. The found asymmetric Brewster angles at interfaces of regions with different DMI strengths, adjustable by magnetic field, support the conclusion that heterochiral ferromagnetic structures are an ideal platform for versatile spin-wave guides. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000428238600006 | Publication Date | 2018-03-26 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 20 | Open Access |
|
| Notes | This work was supported by the Research Foundation- Flanders (FWO-Vlaanderen) through Project No. G098917N. | Approved | Most recent IF: 3.836 | ||
| Call Number | CMT @ cmt @c:irua:150118UA @ admin @ c:irua:150118 | Serial | 4915 | ||
| Permanent link to this record | |||||
| Author | Cavalcante, L.S.R.; Chaves, A.; Van Duppen, B.; Peeters, F.M.; Reichman, D.R. | ||||
| Title | Electrostatics of electron-hole interactions in van der Waals heterostructures | Type | A1 Journal article | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 97 | Issue | 12 | Pages | 125427 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| 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. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000427983700007 | Publication Date | 2018-03-21 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 22 | Open Access |
|
| 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 | ||
| Call Number | CMT @ cmt @c:irua:150835UA @ admin @ c:irua:150835 | Serial | 4953 | ||
| Permanent link to this record | |||||
| Author | Kuo, C.-T.; Lin, S.-C.; Ghiringhelli, G.; Peng, Y.; De Luca, G.M.; Di Castro, D.; Betto, D.; Gehlmann, M.; Wijnands, T.; Huijben, M.; Meyer-Ilse, J.; Gullikson, E.; Kortright, J.B.; Vailionis, A.; Gauquelin, N.; Verbeeck, J.; Gerber, T.; Balestrino, G.; Brookes, N.B.; Braicovich, L.; Fadley, C.S. | ||||
| Title | Depth-resolved resonant inelastic x-ray scattering at a superconductor/half-metallic-ferromagnet interface through standing wave excitation | Type | A1 Journal article | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 98 | Issue | 23 | Pages | 235146 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | We demonstrate that combining standing wave (SW) excitation with resonant inelastic x-ray scattering (RIXS) can lead to depth resolution and interface sensitivity for studying orbital and magnetic excitations in correlated oxide heterostructures. SW-RIXS has been applied to multilayer heterostructures consisting of a superconductor La1.85Sr0.15CuO4 (LSCO) and a half-metallic ferromagnet La0.67Sr0.33MnO3 (LSMO). Easily observable SW effects on the RIXS excitations were found in these LSCO/LSMO multilayers. In addition, we observe different depth distribution of the RIXS excitations. The magnetic excitations are found to arise from the LSCO/LSMO interfaces, and there is also a suggestion that one of the dd excitations comes from the interfaces. SW-RIXS measurements of correlated-oxide and other multilayer heterostructures should provide unique layer-resolved insights concerning their orbital and magnetic excitations, as well as a challenge for RIXS theory to specifically deal with interface effects. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000454160800004 | Publication Date | 2018-12-21 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | 5 | Open Access |
|
| Notes | J.V. and N.G. acknowledge ˝ funding through the GOA project “Solarpaint” of the University of Antwerp. The microscope used in this work was partly funded by the Hercules Fund from the Flemish Government. | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:156784 | Serial | 5363 | ||
| Permanent link to this record | |||||
| Author | Ceyhan, E.; Yagmurcukardes, M.; Peeters, F.M.; Sahin, H. | ||||
| Title | Electronic and magnetic properties of single-layer FeCl₂ with defects | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 103 | Issue | 1 | Pages | 014106 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The formation of lattice defects and their effect on the electronic properties of single-layer FeCl2 are investigated by means of first-principles calculations. Among the vacancy defects, namely mono-, di-, and three-Cl vacancies and mono-Fe vacancy, the formation of mono-Cl vacancy is the most preferable. Comparison of two different antisite defects reveals that the formation of the Fe-antisite defect is energetically preferable to the Cl-antisite defect. While a single Cl vacancy leads to a 1 mu(B) decrease in the total magnetic moment of the host lattice, each Fe vacant site reduces the magnetic moment by 4 mu(B). However, adsorption of an excess Cl atom on the surface changes the electronic structure to a ferromagnetic metal or to a ferromagnetic semiconductor depending on the adsorption site without changing the ferromagnetic state of the host lattice. Both Cl-antisite and Fe-antisite defected domains change the magnetic moment of the host lattice by -1 mu(B) and +3 mu(B), respectively. The electronic ground state of defected structures reveals that (i) single-layer FeCl2 exhibits half-metallicity under the formation of vacancy and Cl-antisite defects; (ii) ferromagnetic metallicity is obtained when a single Cl atom is adsorbed on upper-Cl and Fe sites, respectively; and (iii) ferromagnetic semiconducting behavior is found when a Cl atom is adsorbed on a lower-Cl site or a Fe-antisite defect is formed. Simulated scanning electron microscope images show that atomic-scale identification of defect types is possible from their electronic charge density. Further investigation of the periodically Fe-defected structures reveals that the formation of the single-layer FeCl3 phase, which is a dynamically stable antiferromagnetic semiconductor, is possible. Our comprehensive analysis on defects in single-layer FeCl2 will complement forthcoming experimental observations. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000606969400002 | Publication Date | 2021-01-13 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | 5 | Open Access |
Not_Open_Access |
| Notes | ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and by Flemish Supercomputer Center (VSC). H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 117F095. M.Y. was supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:176039 | Serial | 6689 | ||
| Permanent link to this record | |||||
| Author | Wang, J.; Van Pottelberge, R.; Zhao, W.-S.; Peeters, F.M. | ||||
| Title | Coulomb impurity on a Dice lattice : atomic collapse and bound states | Type | A1 Journal article | ||
| Year | 2022 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 105 | Issue | 3 | Pages | 035427 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The modification of the quantum states in a Dice lattice due to a Coulomb impurity are investigated. The energy-band structure of a pristine Dice lattice consists of a Dirac cone and a flat band at the Dirac point. We use the tight-binding formalism and find that the flat band states transform into a set of discrete bound states whose electron density is localized on a ring around the impurity mainly on two of the three sublattices. Its energy is proportional to the strength of the Coulomb impurity. Beyond a critical strength of the Coulomb potential atomic collapse states appear that have some similarity with those found in graphene with the difference that the flat band states contribute with an additional ringlike electron density that is spatially decoupled from the atomic collapse part. At large value of the strength of the Coulomb impurity the flat band bound states anticross with the atomic collapse states. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000749375200002 | Publication Date | 2022-01-28 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | 1 | Open Access |
Not_Open_Access |
| Notes | Approved | Most recent IF: 3.7 | |||
| Call Number | UA @ admin @ c:irua:186387 | Serial | 6977 | ||
| Permanent link to this record | |||||
| Author | Hassani, H.; Partoens, B.; Bousquet, E.; Ghosez, P. | ||||
| Title | First-principles study of lattice dynamical properties of the room-temperature P2₁/n and ground-state P2₁/c phases of WO₃ | Type | A1 Journal article | ||
| Year | 2022 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 105 | Issue | 1 | Pages | 014107 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Using first-principles density functional theory, we investigate the dynamical properties of the roomtemperature P21/n and ground-state P21/c phases of WO3. As a preliminary step, we assess the validity of various standard and hybrid functionals, concluding that the best description is achieved with the B1-WC hybrid functional while a reliable description can also be provided using the standard LDA functional. We also carefully rediscuss the structure and energetics of all experimentally observed and a few hypothetical metastable phases in order to provide deeper insight into the unusual sequence of phase transition of WO3 with temperature. Then, we provide a comprehensive theoretical study of the lattice dynamical properties of the P21/n and P21/c phases, reporting zone-center phonons, infrared and Raman spectra, as well as the full phonon dispersion curves, which attest to the dynamical stability of both phases. We carefully discuss the spectra, explaining the physical origin of their main features and evolution from one phase to another. We reveal a systematic connection between the dynamical and structural properties of WO3, highlighting that the number of peaks in the high-frequency range of the Raman spectrum appears as a fingerprint of the number of antipolar distortions that are present in the structure and a practical way to discriminate between the different phases. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000747398100004 | Publication Date | 2022-01-24 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | 5 | Open Access |
Not_Open_Access |
| Notes | Approved | Most recent IF: 3.7 | |||
| Call Number | UA @ admin @ c:irua:186388 | Serial | 6994 | ||
| Permanent link to this record | |||||
| Author | Pandey, T.; Covaci, L.; Milošević, M.V.; Peeters, F.M. | ||||
| Title | Flexoelectricity and transport properties of phosphorene nanoribbons under mechanical bending | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 103 | Issue | 23 | Pages | 235406 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We examine from first principles the flexoelectric properties of phosphorene nanoribbons under mechanical bending along armchair and zigzag directions. In both cases we find that the radial polarization depends linearly on the strain gradient. The flexoelectricity along the armchair direction is over 40% larger than along the zigzag direction. The obtained flexoelectric coefficients of phosphorene are four orders of magnitude larger than those of graphene and comparable to transition metal dichalcogenides. Analysis of charge density shows that the flexoelectricity mainly arises from the pz orbitals of phosphorus atoms. The electron mobilities in bent phosphorene can be enhanced by over 60% along the armchair direction, which is significantly higher than previous reports of mobility tuned by uniaxial strain. Our results indicate phosphorene is a candidate for a two-dimensional material applicable in flexible-electronic devices. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000657129800006 | Publication Date | 2021-06-02 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | 8 | Open Access |
Not_Open_Access |
| Notes | Approved | Most recent IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:179109 | Serial | 6996 | ||
| Permanent link to this record | |||||
| Author | Varjovi, M.J.; Yagmurcukardes, M.; Peeters, F.M.; Durgun, E. | ||||
| Title | Janus two-dimensional transition metal dichalcogenide oxides: First-principles investigation of WXO monolayers with X = S, Se, and Te | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 103 | Issue | 19 | Pages | 195438 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Structural symmetry breaking in two-dimensional materials can lead to superior physical properties and introduce an additional degree of piezoelectricity. In the present paper, we propose three structural phases (1H, 1T, and 1T') of Janus WXO (X = S, Se, and Te) monolayers and investigate their vibrational, thermal, elastic, piezoelectric, and electronic properties by using first-principles methods. Phonon spectra analysis reveals that while the 1H phase is dynamically stable, the 1T phase exhibits imaginary frequencies and transforms to the distorted 1T' phase. Ab initio molecular dynamics simulations confirm that 1H- and 1T'-WXO monolayers are thermally stable even at high temperatures without any significant structural deformations. Different from binary systems, additional Raman active modes appear upon the formation of Janus monolayers. Although the mechanical properties of 1H-WXO are found to be isotropic, they are orientation dependent for 1T'-WXO. It is also shown that 1H-WXO monolayers are indirect band-gap semiconductors and the band gap narrows down the chalcogen group. Except 1T'-WSO, 1T'-WXO monolayers have a narrow band gap correlated with the Peierls distortion. The effect of spin-orbit coupling on the band structure is also examined for both phases and the alteration in the band gap is estimated. The versatile mechanical and electronic properties of Janus WXO monolayers together with their large piezoelectric response imply that these systems are interesting for several nanoelectronic applications. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000655902600004 | Publication Date | 2021-05-26 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | 48 | Open Access |
Not_Open_Access |
| Notes | Approved | Most recent IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:179050 | Serial | 7000 | ||
| Permanent link to this record | |||||
| Author | Yagmurcukardes, M.; Mogulkoc, Y.; Akgenc, B.; Mogulkoc, A.; Peeters, F.M. | ||||
| Title | Prediction of monoclinic single-layer Janus Ga₂ Te X (X = S and Se) : strong in-plane anisotropy | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 104 | Issue | 4 | Pages | 045425 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | By using density functional theory (DFT) based first-principles calculations, electronic, vibrational, piezo-electric, and optical properties of monoclinic Janus single-layer Ga2TeX (X = S or Se) are investigated. The dynamical, mechanical, and thermal stability of the proposed Janus single layers are verified by means of phonon bands, stiffness tensor, and quantum molecular dynamics simulations. The calculated vibrational spectrum reveals the either pure or coupled optical phonon branches arising from Ga-Te and Ga-X atoms. In addition to the in-plane anisotropy, single-layer Janus Ga2TeX exhibits additional out-of-plane asymmetry, which leads to important consequences for its electronic and optical properties. Electronic band dispersions indicate the direct band-gap semiconducting nature of the constructed Janus structures with energy band gaps falling into visible spectrum. Moreover, while orientation-dependent linear-elastic properties of Janus single layers indicate their strong anisotropy, the calculated in-plane stiffness values reveal the ultrasoft nature of the structures. In addition, predicted piezoelectric coefficients show that while there is a strong in-plane anisotropy between piezoelectric constants along armchair (AC) and zigzag (ZZ) directions, there exists a tiny polarization along the out-of-plane direction as a result of the formation of Janus structure. The optical response to electromagnetic radiation has been also analyzed through density functional theory by considering the independent-particle approximation. Finally, the optical spectra of Janus Ga2TeX structures is investigated and it showed a shift from the ultraviolet region to the visible region. The fact that the spectrum is between these regions will allow it to be used in solar energy and many nanoelectronics applications. The predicted monoclinic single-layer Janus Ga2TeX are relevant for promising applications in optoelectronics, optical dichroism, and anisotropic nanoelasticity. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000678811100007 | Publication Date | 2021-07-26 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | 3 | Open Access |
Not_Open_Access |
| Notes | Approved | Most recent IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:180404 | Serial | 7013 | ||
| Permanent link to this record | |||||
| Author | Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V. | ||||
| Title | Controlling the hybridization gap and transport in a thin-film topological insulator : effect of strain, and electric and magnetic field | Type | A1 Journal article | ||
| Year | 2022 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 106 | Issue | 3 | Pages | 035119-7 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | In a thin-film topological insulator (TI), the edge states on two surfaces may couple by quantum tunneling, opening a gap known as the hybridization gap. Controlling the hybridization gap and transport has a variety of potential uses in photodetection and energy-harvesting applications. In this paper, we report the effect of strain, and electric and magnetic field, on the hybridization gap and transport in a thin Bi2Se3 film, investigated within the tight-binding theoretical framework. We demonstrate that vertical compression decreases the hybridization gap, as does tensile in-plane strain. Applying an electric field breaks the inversion symmetry and leads to a Rashba-like spin splitting proportional to the electric field, hence closing and reopening the gap. The influence of a magnetic field on thin-film TI is also discussed, starting from the role of an out-of-plane magnetic field on quantum Hall states. We further demonstrate that the hybridization gap can be controlled by an in-plane magnetic field, and that by applying a sufficiently strong field a quantum phase transition from an insulator to a semimetal can be achieved. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000832277500001 | Publication Date | 2022-07-13 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | Open Access |
Not_Open_Access | |
| Notes | Approved | Most recent IF: 3.7 | |||
| Call Number | UA @ admin @ c:irua:189515 | Serial | 7140 | ||
| Permanent link to this record | |||||
| Author | Cadorim, L.R.; de Toledo, L.V.; Ortiz, W.A.; Berger, J.; Sardella, E. | ||||
| Title | Closed vortex state in three-dimensional mesoscopic superconducting films under an applied transport current | Type | A1 Journal article | ||
| Year | 2023 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 107 | Issue | 9 | Pages | 094515-94518 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | By using the full 3D generalized time-dependent Ginzbug-Landau equation, we study a long superconducting film of finite width and thickness under an applied transport current. We show that, for sufficiently large thickness, the vortices and the antivortices become curved before they annihilate each other. As they approach the center of the sample, their ends combine, producing a single closed vortex. We also determine the critical values of the thickness for which the closed vortex sets in for different values of the Ginzburg-Ladau parameter. Finally, we propose a model of how to detect a closed vortex experimentally. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000957055800002 | Publication Date | 2023-03-20 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | Open Access |
Not_Open_Access | |
| Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:196079 | Serial | 7673 | ||
| Permanent link to this record | |||||
| Author | Zuniga-Puelles, E.; Levytskyi, V.; Özden, A.; Guerel, T.; Bulut, N.; Himcinschi, C.; Sevik, C.; Kortus, J.; Gumeniuk, R. | ||||
| Title | Thermoelectric properties and scattering mechanisms in natural PbS | Type | A1 Journal article | ||
| Year | 2023 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 107 | Issue | 19 | Pages | 195203-195215 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | X-ray diffraction and energy dispersive x-ray spectroscopic analyses showed a natural galena (PbS) crystal from Freiberg in Saxony (Germany) to be a single phase specimen [rock salt (NaCl) structure type, space group Fm3m, a = 5.932(1) angstrom] with stoichiometric composition and an enhanced dislocation density (8 approximate to 1011 cm-2). The latter parameter leads to an increase of the electrical resistivity in the high-temperature regime, as well as to the appearance of phonon resonance with a characteristic frequency coPR = 3.8(1) THz. Being in the same range (i.e., 3-5.5 THz) with the sulfur optical modes of highest group velocities, it results in a drastic reduction (by similar to 75%) of thermal conductivity (K) at lower temperatures (i.e., < 100 K), as well as in the appearance of a characteristic minimum in K at T approximate to 30 K. Furthermore, the studied galena is characterized by phonon-drag behavior and by temperature dependent switch of the charge carrier scattering mechanism regime (i.e., scattering on dislocations for T < 100 K, on acoustic phonons for 100 K < T < 170 K and on both acoustic and optical phonons for 170 K < T < 300 K). The combined theoretical calculation and optical spectroscopic study confirm this mineral to be a direct gap degenerate semiconductor. The possible origins of the second-order Raman spectrum are discussed. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001009980400008 | Publication Date | 2023-05-30 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| 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 | Open Access |
Not_Open_Access | |
| Notes | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:197808 | Serial | 8943 | ||
| Permanent link to this record | |||||
| Author | Claes, J.; Partoens, B.; Lamoen, D. | ||||
| Title | Decoupled DFT-1/2 method for defect excitation energies | Type | A1 Journal Article | ||
| Year | 2023 | Publication | Physical Review B | Abbreviated Journal | Phys. Rev. B |
| Volume | 108 | Issue | 12 | Pages | 125306 |
| Keywords | A1 Journal Article; Condensed Matter Theory (CMT) ; | ||||
| Abstract | The DFT-1/2 method is a band-gap correction with GW precision at a density functional theory (DFT) computational cost. The method was also extended to correct the gap between defect levels, allowing for the calculation of optical transitions. However, this method fails when the atomic character of the occupied and unoccupied defect levels is similar as we illustrate by two examples, the tetrahedral hydrogen interstitial and the negatively charged vacancy in diamond. We solve this problem by decoupling the effect of the occupied and unoccupied defect levels and call this the decoupled DFT-1/2 method for defects. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 001089302800003 | Publication Date | 2023-09-25 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950 | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | 3.7 | Times cited | Open Access |
Not_Open_Access | |
| Notes | This work was supported by the FWO (Research Foundation-Flanders), Project No. G0D1721N. This work was performed in part using HPC resources from the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWO-Vlaanderen and the Flemish Government department EWI (Economie, Wetenschap & Innovatie). | Approved | Most recent IF: 3.7; 2023 IF: 3.836 | ||
| Call Number | CMT @ cmt @c:irua:201287 | Serial | 8976 | ||
| Permanent link to this record | |||||