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| Author | Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G. | ||||
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Critical behavior of the ferromagnets CrI₃, CrBr₃, and CrGeTe₃ and the antiferromagnet FeCl₂ : a detailed first-principles study | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 103 | Issue | 1 | Pages | 014432 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We calculate the Curie temperature of layered ferromagnets, chromium tri-iodide (CrI3), chromium tri-bromide (CrBr3), chromium germanium tri-telluride (CrGeTe3), and the Ned temperature of a layered antiferromagnet iron di-chloride (FeCl2), using first-principles density functional theory calculations and Monte Carlo simulations. We develop a computational method to model the magnetic interactions in layered magnetic materials and calculate their critical temperature. We provide a unified method to obtain the magnetic exchange parameters (J) for an effective Heisenberg Hamiltonian from first principles, taking into account both the magnetic ansiotropy as well as the out-of-plane interactions. We obtain the magnetic phase change behavior, in particular the critical temperature, from the susceptibility and the specific-heat, calculated using the three-dimensional Monte Carlo (METROPOLIS) algorithm. The calculated Curie temperatures for ferromagnetic materials (CrI3, CrBr3, and CrGeTe3), match well with experimental values. We show that the interlayer interaction in bulk CrI3 with R (3) over bar stacking is significantly stronger than the C2/m stacking, in line with experimental observations. We show that the strong interlayer interaction in R (3) over bar CrI3 results in a competition between the in-plane and the out-of-plane magnetic easy axes. Finally, we calculate the Ned temperature of FeCl2 to be 47 +/- 8 K and show that the magnetic phase transition in FeCl2 occurs in two steps with a high-temperature intralayer ferromagnetic phase transition and a low-temperature interlayer antiferromagnetic phase transition. | ||||
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| Language | Wos | 000609012000002 | Publication Date | 2021-01-20 | |
| 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 | 3.836 | Times cited | Open Access | OpenAccess | |
| Notes | ; The project or effort depicted was or is sponsored by the Department of Defense, Defense Threat Reduction Agency Grant No. HDTRA1-18-1-0018. The content of the information does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. This work was supported by imec's Industrial Affiliation Program. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:176081 | Serial | 6686 | ||
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| 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. | ||||
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| 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 | 3 | Open Access | Not_Open_Access |
| Notes | Approved | Most recent IF: 3.7 | |||
| Call Number | UA @ admin @ c:irua:186387 | Serial | 6977 | ||
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| Author | Dharma-Wardana, M.W.C.; Neilson, D.; Peeters, F.M. | ||||
| Title |
Correlation functions in electron-electron and electron-hole double quantum wells : temperature, density, and barrier-width dependence | Type | A1 Journal article | ||
| Year | 2019 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 99 | Issue | 3 | Pages | 035303 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The classical-map hypernetted-chain (CHNC) scheme, developed for treating fermion fluids at strong coupling and at finite temperatures, is applied to electron-electron and electron-hole double quantum wells. The pair-distribution functions and the local field factors needed in linear-response theory are determined for a range of temperatures, carrier densities, and barrier widths typical for experimental double-quantum-well systems in GaAs-GaAlAs. For electron-hole double quantum wells, a large enhancement in the pair-distribution functions is found for small carrier separations. The CHNC equations for electron-hole systems no longer hold at low densities where bound-state formation occurs. | ||||
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| Language | Wos | 000455163800004 | Publication Date | 2019-01-08 | |
| 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; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 6 | Open Access | |
| Notes | ; This work was partially supported by the Flemish Science Foundation (FWO-Vl). M.W.C.D.-W. acknowledges with thanks the hospitality and stimulating atmosphere of the Condensed Matter Theory group at the University of Antwerp. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:156734 | Serial | 5201 | ||
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| Author | De Beule, C.; Ziani, N.T.; Zarenia, M.; Partoens, B.; Trauzettel, B. | ||||
| Title |
Correlation and current anomalies in helical quantum dots | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 94 | Issue | 94 | Pages | 155111 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We theoretically investigate the ground-state properties of a quantum dot defined on the surface of a strong three-dimensional time-reversal invariant topological insulator. Confinement is realized by ferromagnetic barriers and Coulomb interaction is treated numerically for up to seven electrons in the dot. Experimentally relevant intermediate interaction strengths are considered. The topological origin of the dot has several consequences: (i) spin polarization increases and the ground state exhibits quantum phase transitions at specific angular momenta as a function of interaction strength, (ii) the onset of Wigner correlations takes place mainly in one spin channel, and (iii) the ground state is characterized by a robust persistent current that changes sign as a function of the distance from the center of the dot. | ||||
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| Language | Wos | 000385242200001 | Publication Date | 2016-10-07 | |
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| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 3 | Open Access | |
| Notes | ; We thank F. Cavaliere, F. Crepin, C. Felser, and B. Yan for interesting discussions, and S. Curreli for performing the finite-element calculation of the magnetic field in COMSOL. C.D.B. and M.Z. are supported by the Flemish Research Foundation (FWO). N.T.Z. and B.T. acknowledge financial support by the DFG (SPP1666 and SFB1170 “ToCoTronics”), the Helmholtz Foundation (VITI), and the ENB Graduate School on “Topological Insulators.” ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:137234 | Serial | 4351 | ||
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| 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. | ||||
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| 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 | 7 | Open Access | Not_Open_Access |
| Notes | Approved | Most recent IF: 3.7 | |||
| Call Number | UA @ admin @ c:irua:189515 | Serial | 7140 | ||
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| Author | Wang, J.; Van Pottelberge, R.; Jacobs, A.; Van Duppen, B.; Peeters, F.M. | ||||
| Title |
Confinement and edge effects on atomic collapse in graphene nanoribbons | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 103 | Issue | 3 | Pages | 035426 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Atomic collapse in graphene nanoribbons behaves in a fundamentally different way as compared to monolayer graphene due to the presence of multiple energy bands and the effect of edges. For armchair nanoribbons we find that bound states gradually transform into atomic collapse states with increasing impurity charge. This is very different in zigzag nanoribbons where multiple quasi-one-dimensional bound states are found that originates from the zero-energy zigzag edge states. They are a consequence of the flat band and the electron distribution of these bound states exhibits two peaks. The lowest-energy edge state transforms from a bound state into an atomic collapse resonance and shows a distinct relocalization from the edge to the impurity position with increasing impurity charge. | ||||
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| Language | Wos | 000610779200008 | Publication Date | 2021-01-22 | |
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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 | OpenAccess |
| Notes | Approved | Most recent IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:176585 | Serial | 6719 | ||
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| Author | Vanderveken, F.; Mulkers, J.; Leliaert, J.; Van Waeyenberge, B.; Sorée, B.; Zografos, O.; Ciubotaru, F.; Adelmann, C. | ||||
| Title |
Confined magnetoelastic waves in thin waveguides | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 103 | Issue | 5 | Pages | 054439 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The characteristics of confined magnetoelastic waves in nanoscale ferromagnetic magnetostrictive waveguides have been investigated by a combination of analytical and numerical calculations. The presence of both magnetostriction and inverse magnetostriction leads to the coupling between confined spin waves and elastic Lamb waves. Numerical simulations of the coupled system have been used to extract the dispersion relations of the magnetoelastic waves as well as their mode profiles. | ||||
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| Language | Wos | 000627548800003 | Publication Date | 2021-02-26 | |
| 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 | Open Access | OpenAccess | |
| Notes | Approved | Most recent IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:177607 | Serial | 6976 | ||
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| Author | Topalovic, D.B.; Arsoski, V.V.; Tadic, M.Z.; Peeters, F.M. | ||||
| Title |
Confined electron states in two-dimensional HgTe in magnetic field : quantum dot versus quantum ring behavior | Type | A1 Journal article | ||
| Year | 2019 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 100 | Issue | 12 | Pages | 125304 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We investigate the electron states and optical absorption in square- and hexagonal-shaped two-dimensional (2D) HgTe quantum dots and quantum rings in the presence of a perpendicular magnetic field. The electronic structure is modeled by means of the sp(3)d(5)s* tight-binding method within the nearest-neighbor approximation. Both bulklike and edge states appear in the energy spectrum. The bulklike states in quantum rings exhibit Aharonov-Bohm oscillations in magnetic field, whereas no such oscillations are found in quantum dots, which is ascribed to the different topology of the two systems. When magnetic field varies, all the edge states in square quantum dots appear as quasibands composed of almost fully flat levels, whereas some edge states in quantum rings are found to oscillate with magnetic field. However, the edge states in hexagonal quantum dots are localized like in rings. The absorption spectra of all the structures consist of numerous absorption lines, which substantially overlap even for small line broadening. The absorption lines in the infrared are found to originate from transitions between edge states. It is shown that the magnetic field can be used to efficiently tune the optical absorption of HgTe 2D quantum dot and quantum ring systems. | ||||
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| Language | Wos | 000486638400007 | Publication Date | 2019-09-16 | |
| 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 | 3.836 | Times cited | 4 | Open Access | |
| Notes | ; This work was supported by Projects No. III 41028, No. III 42008, and No. III 45003 funded by the Serbian Ministry of Education, Science and Technological Development, and the Flemish Science Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:162787 | Serial | 5409 | ||
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| Author | Aslani, Z.; Sisakht, E.T.; Fazileh, F.; Ghorbanfekr-Kalashami, H.; Peeters, F.M. | ||||
| Title |
Conductance fluctuations of monolayer GeSnH2$ in the topological phase using a low-energy effective tight-binding Hamiltonian | Type | A1 Journal article | ||
| Year | 2019 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 99 | Issue | 11 | Pages | 115421 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | An effective tight-binding (TB) Hamiltonian for monolayer GeSnH2 is constructed which has an inversion-asymmetric honeycomb structure. The low-energy band structure of our TB model agrees very well with previous ab initio calculations even under biaxial tensile strain. Our model predicts a phase transition at 7.5% biaxial tensile strain in agreement with DFT calculations. Upon 8.5% strain the system exhibits a band gap of 134 meV, suitable for room temperature applications. It is shown that an external applied magnetic field produces a special phase which is a combination of the quantum Hall (QH) and quantum spin Hall (QSH) phases; and at a critical magnetic field strength the QSH phase completely disappears. The topological nature of the phase transition is confirmed from: (1) the calculation of the Z(2) topological invariant, and (2) quantum transport properties of disordered GeSnH2 nanoribbons which allows us to determine the universality class of the conductance fluctuations. The application of an external applied magnetic field reduces the conductance fluctuations by a factor of root 2. | ||||
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| Language | Wos | 000461958900006 | Publication Date | 2019-03-15 | |
| 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 | |
| Notes | ; This work was supported by the FLAG-ERA project TRANS-2D-TMD. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:158538 | Serial | 5199 | ||
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| Author | Gurel, T.; Altunay, Y.A.; Bulut, P.; Yildirim, S.; Sevik, C. | ||||
| Title |
Comprehensive investigation of the extremely low lattice thermal conductivity and thermoelectric properties of BaIn₂Te₄ | Type | A1 Journal article | ||
| Year | 2022 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 106 | Issue | 19 | Pages | 195204-195210 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Recently, an extremely low lattice thermal conductivity value has been reported for the alkali-based telluride material BaIn2Te4. The value is comparable with low-thermal conductivity metal chalcogenides, and the glass limit is highly intriguing. Therefore, to shed light on this issue, we performed first-principles phonon thermal transport calculations. We predicted highly anisotropic lattice thermal conductivity along different directions via the solution of the linearized phonon Boltzmann transport equation. More importantly, we determined several different factors as the main sources of the predicted ultralow lattice thermal conductivity of this crystal, such as the strong interactions between low-frequency optical phonons and acoustic phonons, small phonon group velocities, and lattice anharmonicity indicated by large negative mode Gruneisen parameters. Along with thermal transport calculations, we also investigated the electronic transport properties by accurately calculating the scattering mechanisms, namely the acoustic deformation potential, ionized impurity, and polar optical scatterings. The inclusion of spin-orbit coupling (SOC) for electronic structure is found to strongly affect the p-type Seebeck coefficients. Finally, we calculated the thermoelectric properties accurately, and the optimal ZT value of p-type doping, which originated from high Seebeck coefficients, was predicted to exceed unity after 700 K and have a direction averaged value of 1.63 (1.76 in the y-direction) at 1000 K around 2 x 1020 cm-3 hole concentration. For n-type doping, a ZT around 3.2 x 1019 cm-3 concentration was predicted to be a direction-averaged value of 1.40 (1.76 in the z-direction) at 1000 K, mostly originating from its high electron mobility. With the experimental evidence of high thermal stability, we showed that the BaIn2Te4 compound has the potential to be a promising mid- to high-temperature thermoelectric material for both p-type and n-type systems with appropriate doping. | ||||
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| Language | Wos | 000918954800001 | Publication Date | 2022-11-21 | |
| 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 | 3.7 | Times cited | Open Access | OpenAccess | |
| Notes | Approved | Most recent IF: 3.7 | |||
| Call Number | UA @ admin @ c:irua:194384 | Serial | 7290 | ||
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| Author | Van Pottelberge, R.; Zarenia, M.; Peeters, F.M. | ||||
| Title |
Comment on “Impurity spectra of graphene under electric and magnetic fields” | Type | Editorial | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 97 | Issue | 20 | Pages | 207403 |
| Keywords | Editorial; Condensed Matter Theory (CMT) | ||||
| Abstract | In a recent paper [Phys. Rev. B 89, 155403 (2014)], the authors investigated the spectrum of a Coulomb impurity in graphene in the presence of magnetic and electric fields using the coupled series expansion approach. In the first part of their paper, they investigated how Coulomb impurity states collapse in the presence of a perpendicular magnetic field. We argue that the obtained spectrum does not give information about the atomic collapse and that their interpretation of the spectrum regarding atomic collapse is not correct. We also argue that the obtained results are only valid up to the dimensionless charge vertical bar alpha vertical bar = 0.5 and, to obtain correct results for alpha > 0.5, a proper regularization of the Coulomb interaction is required. Here we present the correct numerical results for the spectrum for arbitrary values of alpha. | ||||
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| Publisher | Amer physical soc | Place of Publication | College pk | Editor | |
| Language | Wos | 000433288800015 | Publication Date | 2018-05-29 | |
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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 | 5 | Open Access | |
| Notes | ; We thank Matthias Van der Donck for fruitful discussions. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem funding of the Flemish Government. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:152042UA @ admin @ c:irua:152042 | Serial | 5017 | ||
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| Author | Van Pottelberge, R. | ||||
| Title |
Comment on “Electron states for gapped pseudospin-1 fermions in the field of a charged impurity” | Type | Editorial | ||
| Year | 2020 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 101 | Issue | 19 | Pages | 197102-197103 |
| Keywords | Editorial; Condensed Matter Theory (CMT) | ||||
| Abstract | In a recent paper [Phys. Rev. B 99, 155124 (2019)], the spectrum of a regularized Coulomb charge was studied in gapped pseudospin-1 systems generated by an alpha – T-3 lattice. The electronic spectrum was studied as a function of the impurity strength Z alpha. However, the results and conclusions on the behavior of the flatband states as a function of the impurity strength are incomplete. In this Comment, I argue that because of the dispersionless nature of the flatband, the states spread out under the influence of a charged impurity forming a continuous band of states. I support my arguments with explicit numerical calculations which show the emergence of a continuum of states. | ||||
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| Language | Wos | 000533793600004 | Publication Date | 2020-05-20 | |
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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 | Open Access | ||
| Notes | ; I would like to acknowledge very insightful discussions with the authors of the commented paper (V. P. Gusynin, E. V. Gorbar, and D. O. Oriekhov). F. M. Peeters is acknowledged for interesting discussions and proofreading. This research was supported by the Flemish Science Foundation through an aspirant research grant for R.V.P. ; | Approved | Most recent IF: 3.7; 2020 IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:169476 | Serial | 6472 | ||
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| Author | Van der Donck, M.; Peeters, F.M.; Van Duppen, B. | ||||
| Title |
Comment on “Creating in-plane pseudomagnetic fields in excess of 1000 T by misoriented stacking in a graphene bilayer” | Type | Editorial | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 93 | Issue | 93 | Pages | 247401 |
| Keywords | Editorial; Condensed Matter Theory (CMT) | ||||
| Abstract | In a recent paper [Phys. Rev. B 89, 125418 (2014)], the authors argue that it is possible to map the electronic properties of twisted bilayer graphene to those of bilayer graphene in an in-plane magnetic field. However, their description of the low-energy dynamics of twisted bilayer graphene is restricted to the extended zone scheme and therefore neglects the effects of the superperiodic structure. If the energy spectrum is studied in the supercell Brillouin zone, we find that the comparison with an in-plane magnetic field fails because (i) the energy spectra of the two situations exhibit different symmetries and (ii) the low-energy spectra are very different. | ||||
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| Publisher | Amer physical soc | Place of Publication | College pk | Editor | |
| Language | Wos | 000377802200009 | Publication Date | 2016-06-14 | |
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| ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 6 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:134601 | Serial | 4151 | ||
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| Author | Cadorim, L.R.; de Toledo, L.V.; Ortiz, W.A.; Berger, J.; Sardella, E. | ||||
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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. | ||||
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| Language | Wos | 000957055800002 | Publication Date | 2023-03-20 | |
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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 | 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 | ||
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| Author | Mirzakhani, M.; Peeters, F.M.; Zarenia, M. | ||||
| Title |
Circular quantum dots in twisted bilayer graphene | Type | A1 Journal article | ||
| Year | 2020 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 101 | Issue | 7 | Pages | 075413 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Within a tight-binding approach, we investigate the effect of twisting angle on the energy levels of circular bilayer graphene (BLG) quantum dots (QDs) in both the absence and presence of a perpendicular magnetic field. The QDs are defined by an infinite-mass potential, so that the specific edge effects are not present. In the absence of magnetic field (or when the magnetic length is larger than the moire length), we show that the low-energy states in twisted BLG QDs are completely affected by the formation of moire patterns, with a strong localization at AA-stacked regions. When magnetic field increases, the energy gap of an untwisted BLG QD closes with the edge states, localized at the boundaries between the AA- and AB-stacked spots in a twisted BLG QD. Our observation of the spatial localization of the electrons in twisted BLG QDs can be experimentally probed by low-bias scanning tunneling microscopy measurements. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000512772200004 | Publication Date | 2020-02-13 | |
| 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 | 19 | Open Access | |
| Notes | ; We gratefully acknowledge discussions with I. Snyman. M.Z. acknowledges support from the U.S. Department of Energy (Office of Science) under Grant No. DE-FG0205ER46203. ; | Approved | Most recent IF: 3.7; 2020 IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:166493 | Serial | 6470 | ||
| 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. | ||||
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| 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 | 3.7 | Times cited | Open Access | ||
| Notes | Approved | Most recent IF: 3.7; 2024 IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:205508 | Serial | 9137 | ||
| Permanent link to this record | |||||
| Author | Bacaksiz, C.; Cahangirov, S.; Rubio, A.; Senger, R.T.; Peeters, F.M.; Sahin, H. | ||||
| Title |
Bilayer SnS2 : tunable stacking sequence by charging and loading pressure | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 93 | Issue | 93 | Pages | 125403 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Employing density functional theory-based methods, we investigate monolayer and bilayer structures of hexagonal SnS2, which is a recently synthesized monolayer metal dichalcogenide. Comparison of the 1H and 1T phases of monolayer SnS2 confirms the ground state to be the 1T phase. In its bilayer structure we examine different stacking configurations of the two layers. It is found that the interlayer coupling in bilayer SnS2 is weaker than that of typical transition-metal dichalcogenides so that alternative stacking orders have similar structural parameters and they are separated with low energy barriers. A possible signature of the stacking order in the SnS2 bilayer has been sought in the calculated absorbance and reflectivity spectra. We also study the effects of the external electric field, charging, and loading pressure on the characteristic properties of bilayer SnS2. It is found that (i) the electric field increases the coupling between the layers at its preferred stacking order, so the barrier height increases, (ii) the bang gap value can be tuned by the external E field and under sufficient E field, the bilayer SnS2 can become a semimetal, (iii) the most favorable stacking order can be switched by charging, and (iv) a loading pressure exceeding 3 GPa changes the stacking order. The E-field tunable band gap and easily tunable stacking sequence of SnS2 layers make this 2D crystal structure a good candidate for field effect transistor and nanoscale lubricant applications. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000371405000005 | Publication Date | 2016-03-03 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 38 | Open Access | |
| Notes | ; The calculations were performed at TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). C.B., H.S., and R.T.S. acknowledge support from TUBITAK Project No. 114F397. H.S. is supported by an FWO Pegasus Marie Curie Fellowship. S.C. and A.R. acknowledge financial support from the Marie Curie grant FP7-PEOPLE-2013-IEF Project No. 628876, the European Research Council (ERC-2010-AdG-267374), and Spanish grant Grupos Consolidados (IT578-13). S.C. acknowledges support from the Scientific and Technological Research Council of Turkey (TUBITAK) under Project No. 115F388. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:132345 | Serial | 4144 | ||
| Permanent link to this record | |||||
| Author | Cunha, S.M.; de Costa, D.R.; Pereira Jr, J.M.; Costa Filho, R.N.; Van Duppen, B.; Peeters, F.M. | ||||
| Title |
Band-gap formation and morphing in alpha-T-3 superlattices | Type | A1 Journal article | ||
| Year | 2021 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 104 | Issue | 11 | Pages | 115409 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Electrons in alpha-T-3 lattices behave as condensed-matter analogies of integer-spin Dirac fermions. The three atoms making up the unit cell bestow the energy spectrum with an additional energy band that is completely flat, providing unique electronic properties. The interatomic hopping term, alpha, is known to strongly affect the electronic spectrum of the two-dimensional (2D) lattice, allowing it to continuously morph from graphenelike responses to the behavior of fermions in a dice lattice. For pristine lattice structures the energy bands are gapless, but small deviations in the atomic equivalence of the three sublattices will introduce gaps in the spectrum. It is unknown how these affect transport and electronic properties such as the energy spectrum of superlattice minibands. Here we investigate the dependency of these properties on the parameter a accounting for different symmetry-breaking terms, and we show how it affects band-gap formation. Furthermore, we find that superlattices can force band gaps to close and shift in energy. Our results demonstrate that alpha-T-3 superlattices provide a versatile material for 2D band-gap engineering purposes. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000696091600003 | Publication Date | 2021-09-10 | |
| 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 | 9 | Open Access | OpenAccess |
| Notes | Approved | Most recent IF: 3.836 | |||
| Call Number | UA @ admin @ c:irua:181544 | Serial | 6972 | ||
| Permanent link to this record | |||||
| Author | Milovanović, S.P.; Andelkovic, M.; Covaci, L.; Peeters, F.M. | ||||
| Title |
Band flattening in buckled monolayer graphene | Type | A1 Journal article | ||
| Year | 2020 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 102 | Issue | 24 | Pages | 245427 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT) | ||||
| Abstract | The strain fields of periodically buckled graphene induce a periodic pseudomagnetic field (PMF) that modifies the electronic band structure. From the geometry, amplitude, and period of the periodic pseudomagnetic field, we determine the necessary conditions to access the regime of correlated phases by examining the band flattening. As compared to twisted bilayer graphene the proposed system has the advantages that (1) only a single layer of graphene is needed, (2) one is not limited to hexagonal superlattices, and (3) narrower flat bandwidth and larger separation between flat bands can be induced. We, therefore, propose that periodically strained graphene single layers can become a platform for the exploration of exotic many-body phases. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000602844600007 | Publication Date | 2020-12-28 | |
| 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 | 27 | Open Access | OpenAccess |
| Notes | ; S.P.M. is supported by the Flemish Science Foundation (FWO). We thank E. Y. Andrei, Y. Jiang, and J. Mao for fruitful discussions. ; | Approved | Most recent IF: 3.7; 2020 IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:175021 | Serial | 6684 | ||
| Permanent link to this record | |||||
| Author | Ozbal, G.; Senger, R.T.; Sevik, C.; Sevincli, H. | ||||
| Title |
Ballistic thermoelectric properties of monolayer semiconducting transition metal dichalcogenides and oxides | Type | A1 Journal article | ||
| Year | 2019 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 100 | Issue | 8 | Pages | 085415 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Combining first-principles calculations with Landauer-Mittiker formalism, ballistic thermoelectric transport properties of semiconducting two-dimensional transition metal dichalcogenides (TMDs) and oxides (TMOs) (namely MX2 with M = Cr, Mo, W, Ti, Zr, Hf; X = O, S, Se, Te) are investigated in their 2H and 1T phases. Having computed structural, as well as ballistic electronic and phononic transport properties for all structures, we report the thermoelectric properties of the semiconducting ones. We find that 2H phases of four of the studied structures have very promising thermoelectric properties, unlike their 1T phases. The maximum room temperature p-type thermoelectric figure of merit (ZT) of 1.57 is obtained for 2H-HfSe2, which can be as high as 3.30 at T = 800 K. Additionally, 2H-ZrSe2, 2H-ZrTe2, and 2H-HfS2 have considerable ZT values (both nand p-type), that are above 1 at room temperature. The 1T phases of Zr and Hf-based oxides possess relatively high power factors, however their high lattice thermal conductance values limit their ZT values to below 1 at room temperature. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000480389100007 | Publication Date | 2019-08-12 | |
| 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:193773 | Serial | 7549 | ||
| Permanent link to this record | |||||
| Author | Lane, T.L.M.; Andelkovic, M.; Wallbank, J.R.; Covaci, L.; Peeters, F.M.; Fal'ko, V.I. | ||||
| Title |
Ballistic electron channels including weakly protected topological states in delaminated bilayer graphene | Type | A1 Journal article | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 97 | Issue | 4 | Pages | 045301 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | <script type='text/javascript'>document.write(unpmarked('We show that delaminations in bilayer graphene (BLG) with electrostatically induced interlayer symmetry can provide one with ballistic channels for electrons with energies inside the electrostatically induced BLG gap. These channels are formed by a combination of valley-polarized evanescent states propagating along the delamination edges (which persist in the presence of a strong magnetic field) and standing waves bouncing between them inside the delaminated region (in a strong magnetic field, these transform into Landau levels in the monolayers). For inverted stackings in BLGs on the left and right of the delamination (AB-2ML-BA or BA-2ML-AB, where 2ML indicates two decoupled monolayers of graphene), the lowest-energy ballistic channels are gapless, have linear dispersion, and appear to be weakly topologically protected. When BLG stackings on both sides of the delamination are the same (AB-2ML-AB or BA-2ML-BA), the lowest-energy ballistic channels are gapped, with a gap epsilon(g) scaling as epsilon(g) alpha W-1 with delamination width and epsilon(g) alpha delta(-1) with the on-layer energy difference in the delaminated part of the structure. Depending on the width, delaminations may also support several \u0022higher-energy\u0022 waveguide modes. Our results are based on both the analytical study of the wave matching of Dirac states and tight-binding model calculations, and we analyze in detail the dependence of the delamination spectrum on the electrostatic conditions in the structure, such as the vertical displacement field.')); | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
| Language | Wos | 000419772200005 | Publication Date | 2018-01-11 | |
| 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; WoS citing articles | |
| Impact Factor | 3.836 | Times cited | 11 | Open Access | |
| Notes | ; This work was funded by EPSRC via EPSRC Grand Engineering Chellenges Grant No. EP/N010345, the Manchester NOWNANO CDT EP/L-1548X, the Flemish Science Foundation (FWO-VI), the European Graphene Flagship project, ERC Synergy grant Hetero2D, and FLAG-ERA project TRANS2DTMD. The authors would like to acknowledge useful discussions with M. Zarenia, S. Slizovskiy, E. McCann, and K. Novesolov. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:148441UA @ admin @ c:irua:148441 | Serial | 4868 | ||
| Permanent link to this record | |||||
| Author | Devolder, T.; Bultynck, O.; Bouquin, P.; Nguyen, V.D.; Rao, S.; Wan, D.; Sorée, B.; Radu, I.P.; Kar, G.S.; Couet, S. | ||||
| Title |
Back hopping in spin transfer torque switching of perpendicularly magnetized tunnel junctions | Type | A1 Journal article | ||
| Year | 2020 | Publication | Physical Review B | Abbreviated Journal | Phys Rev B |
| Volume | 102 | Issue | 18 | Pages | 184406 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We analyze the phenomenon of back hopping in spin-torque induced switching of the magnetization in perpendicularly magnetized tunnel junctions. The analysis is based on single-shot time-resolved conductance measurements of the pulse-induced back hopping. Studying several material variants reveals that the back hopping is a feature of the nominally fixed system of the tunnel junction. The back hopping is found to proceed by two sequential switching events that lead to a final state P' of conductance close to-but distinct from-that of the conventional parallel state. The P' state does not exist at remanence. It generally relaxes to the conventional antiparallel state if the current is removed. The P' state involves a switching of the sole spin-polarizing part of the fixed layers. The analysis of literature indicates that back hopping occurs only when the spin-polarizing layer is too weakly coupled to the rest of the fixed system, which justifies a posteriori the mitigation strategies of back hopping that were implemented empirically in spin-transfer-torque magnetic random access memories. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000587594900005 | Publication Date | 2020-11-09 | |
| 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 | ||
| Notes | ; This work was supported in part by the IMEC's Industrial Affiliation Program on STT-MRAM device, and in part by the imec IIAP core CMOS and the Beyond CMOS program of Intel Corporation. T. D. and P. B. thank Jonathan Z. Sun for constructive discussions on the BH phenomenon. ; | Approved | Most recent IF: 3.7; 2020 IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:173524 | Serial | 6458 | ||
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| 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. |
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000345467000003 | Publication Date | 2014-11-20 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
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| ISSN | ISBN | Additional Links | |||
| Impact Factor | Times cited | 17 | Open Access | ||
| Notes | Approved | Most recent IF: NA | |||
| Call Number | EMAT @ emat @ | Serial | 4544 | ||
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| Author | Müller-Caspary, K.; Duchamp, M.; Roesner, M.; Migunov, V.; Winkler, F.; Yang, H.; Huth, M.; Ritz, R.; Simson, M.; Ihle, S.; Soltau, H.; Wehling, T.; Dunin-Borkowski, R.E.; Van Aert, S.; Rosenauer, A. | ||||
| Title |
Atomic-scale quantification of charge densities in two-dimensional materials | Type | A1 Journal article | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 98 | Issue | 12 | Pages | 121408 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The charge density is among the most fundamental solid state properties determining bonding, electrical characteristics, and adsorption or catalysis at surfaces. While atomic-scale charge densities have as yet been retrieved by solid state theory, we demonstrate both charge density and electric field mapping across a mono-/bilayer boundary in 2D MoS2 by momentum-resolved scanning transmission electron microscopy. Based on consistency of the four-dimensional experimental data, statistical parameter estimation and dynamical electron scattering simulations using strain-relaxed supercells, we are able to identify an AA-type bilayer stacking and charge depletion at the Mo-terminated layer edge. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
| Language | Wos | 000445508200004 | Publication Date | 2018-09-24 | |
| 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 | 3.836 | Times cited | 10 | Open Access | OpenAccess |
| Notes | ; K.M.-C. acknowledges funding from the Initiative and Network Fund of the Helmholtz Association (VH-NG-1317) within the framework of the Helmholtz Young Investigator Group moreSTEM at Forschungszentrum Julich, Germany. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:153621 | Serial | 5078 | ||
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| Author | Callewaert, V.; Saniz, R.; Barbiellini, B.; Bansil, A.; Partoens, B. | ||||
| Title |
Application of the weighted-density approximation to the accurate description of electron-positron correlation effects in materials | Type | A1 Journal article | ||
| Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 96 | Issue | 8 | Pages | 085135 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We discuss positron-annihilation lifetimes for a set of illustrative bulk materials within the framework of the weighted-density approximation (WDA). The WDA can correctly describe electron-positron correlations in strongly inhomogeneous systems, such as surfaces, where the applicability of (semi-)local approximations is limited. We analyze the WDA in detail and show that the electrons which cannot screen external charges efficiently, such as the core electrons, cannot be treated accurately via the pair correlation of the homogeneous electron gas. We discuss how this problem can be addressed by reducing the screening in the homogeneous electron gas by adding terms depending on the gradient of the electron density. Further improvements are obtained when core electrons are treated within the LDA and the valence electron using the WDA. Finally, we discuss a semiempirical WDA-based approach in which a sum rule is imposed to reproduce the experimental lifetimes. | ||||
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| 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 | ||
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| Author | Sabzalipour, A.; Partoens, B. | ||||
| 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 |
| Volume | 100 | Issue | 3 | Pages | 035419 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| 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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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000475499200007 | Publication Date | 2019-07-15 | |
| 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 | 2 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:161219 | Serial | 5406 | ||
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| Author | Sanchez-Barriga, J.; Aguilera, I.; Yashina, L., V; Tsukanova, D.Y.; Freyse, F.; Chaika, A.N.; Callaert, C.; Abakumov, A.M.; Hadermann, J.; Varykhalov, A.; Rienks, E.D.L.; Bihlmayer, G.; Blugel, S.; Rader, O. | ||||
| Title |
Anomalous behavior of the electronic structure of (Bi1-xInx)2Se3across the quantum phase transition from topological to trivial insulator | Type | A1 Journal article | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | |
| Volume | 98 | Issue | 23 | Pages | 235110 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Using spin- and angle-resolved photoemission spectroscopy and relativistic many-body calculations, we investigate the evolution of the electronic structure of (Bi1-xInx)(2)Se-3)(2)Se-3 bulk single crystals around the critical point of the trivial to topological insulator quantum-phase transition. By increasing x, we observe how a surface gap opens at the Dirac point of the initially gapless topological surface state of Bi2Se3, leading to the existence of massive fermions. The surface gap monotonically increases for a wide range of x values across the topological and trivial sides of the quantum-phase transition. By means of photon-energy-dependent measurements, we demonstrate that the gapped surface state survives the inversion of the bulk bands which occurs at a critical point near x = 0.055. The surface state exhibits a nonzero in-plane spin polarization which decays exponentially with increasing x, and which persists in both the topological and trivial insulator phases. Our calculations reveal qualitative agreement with the experimental results all across the quantum-phase transition upon the systematic variation of the spin-orbit coupling strength. A non-time-reversal symmetry-breaking mechanism of bulk-mediated scattering processes that increase with decreasing spin-orbit coupling strength is proposed as explanation. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000452322800003 | Publication Date | 2018-12-05 | |
| 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:156240 | Serial | 7462 | ||
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| 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. |
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| 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 | ||
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| Author | Saberi-Pouya, S.; Vazifehshenas, T.; Salavati-fard, T.; Farmanbar, M. | ||||
| Title |
Anisotropic hybrid excitation modes in monolayer and double-layer phosphorene on polar substrates | Type | A1 Journal article | ||
| Year | 2017 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 96 | Issue | 11 | Pages | 115402 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We investigate the anisotropic hybrid surface optical (SO) phonon-plasmon dispersion relations in monolayer and double-layer phosphorene systems located on the polar substrates, such as SiO2, h-BN, and Al2O3. We calculate these hybrid modes by using the dynamical dielectric function in the random phase approximation in which the electron-electron interaction and long-range electric field generated by the substrate SO phonons via Frohlich interaction are taken into account. In the long-wavelength limit, we obtain some analytical expressions for the hybrid SO phonon-plasmon dispersion relations which agree with those obtained from the loss function. Our results indicate a strong anisotropy in SO phonon-plasmon modes, which are stronger along the light-mass direction in our heterostructures. Furthermore, we find that the type of substrate has a significant effect on the dispersion relations of the coupled modes. Importantly, the hybrid excitations are apparently sensitive to the misalignment and separation between layers in double-layer phosphorene. | ||||
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| Publisher | American Physical Society | Place of Publication | New York, N.Y | Editor | |
| Language | Wos | 000408826200004 | Publication Date | 2017-09-01 | |
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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 | 6 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:145665 | Serial | 4737 | ||
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| Author | Saberi-Pouya, S.; Zarenia, M.; Vazifehshenas, T.; Peeters, F.M. | ||||
| Title |
Anisotropic charge density wave in electron-hole double monolayers : applied to phosphorene | Type | A1 Journal article | ||
| Year | 2018 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 98 | Issue | 24 | Pages | 245115 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The possibility of an inhomogeneous charge density wave phase is investigated in a system of two coupled electron and hole monolayers separated by a hexagonal boron nitride insulating layer. The charge-density-wave state is induced through the assumption of negative compressibility of electron/hole gases in a Coulomb drag configuration between the electron and hole sheets. Under equilibrium conditions, we derive analytical expressions for the density oscillation along the zigzag and armchair directions. We find that the density modulation not only depends on the sign of the compressibility but also on the anisotropy of the low-energy bands. Our results are applicable to any two-dimensional system with anisotropic parabolic bands, characterized by different effective masses. For equal effective masses, i.e., isotropic energy bands, our results agree with Hroblak et al. [Phys. Rev. B 96, 075422 (2017)]. Our numerical results are applied to phosphorene. | ||||
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| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000452995600001 | Publication Date | 2018-12-12 | |
| 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 | 3.836 | Times cited | Open Access | ||
| Notes | ; This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government and Iran Science Elites Federation. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ admin @ c:irua:156233 | Serial | 5195 | ||
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