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Author Yagmurcukardes, M.; Torun, E.; Senger, R.T.; Peeters, F.M.; Sahin, H. url  doi
openurl 
  Title (up) Mg(OH)2-WS2 van der Waals heterobilayer : electric field tunable band-gap crossover Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 94 Pages 195403  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Magnesium hydroxide [Mg(OH)(2)] has a layered brucitelike structure in its bulk form and was recently isolated as a new member of two-dimensional monolayer materials. We investigated the electronic and optical properties of monolayer crystals of Mg(OH)(2) and WS2 and their possible heterobilayer structure by means of first-principles calculations. It was found that both monolayers of Mg(OH)(2) and WS2 are direct-gap semiconductors and these two monolayers form a typical van der Waals heterostructure with a weak interlayer interaction and a type-II band alignment with a staggered gap that spatially separates electrons and holes. We also showed that an out-of-plane electric field induces a transition from a staggered to a straddling-type heterojunction. Moreover, by solving the Bethe-Salpeter equation on top of single-shot G(0)W(0) calculations, we show that the low-energy spectrum of the heterobilayer is dominated by the intralyer excitons of the WS2 monolayer. Because of the staggered interfacial gap and the field-tunable energy-band structure, the Mg(OH)(2)-WS2 heterobilayer can become an important candidate for various optoelectronic device applications in nanoscale.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000386769400007 Publication Date 2016-11-03  
  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 ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. is supported by a FWOPegasus Long Marie Curie Fellowship. H.S. and R.T.S. acknowledge support from TUBITAK through Project No. 114F397. H.S. acknowledges support from Bilim Akademisi – The Science Academy, Turkey, under the BAGEP program. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:138205 Serial 4364  
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Author Wang, J.; Andelkovic, M.; Wang, G.; Peeters, F.M. url  doi
openurl 
  Title (up) Molecular collapse in graphene: Sublattice symmetry effect Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 102 Issue 6 Pages 064108-8  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Atomic collapse can be observed in graphene because of its large “effective” fine structure constant, which enables this phenomenon to occur for an impurity charge as low as Z(c) similar to 1-2. Here we investigate the effect of the sublattice symmetry on molecular collapse in two spatially separated charge tunable vacancies, which are located on the same (A-A type) or different (A-B type) sublattices. We find that the broken sublattice symmetry: (1) does not affect the location of the main bonding and antibonding molecular collapse peaks, (2) but shifts the position of the satellite peaks, because they are a consequence of the breaking of the local sublattice symmetry, and (3) there are vacancy characteristic collapse peaks that only occur for A-B type vacancies, which can be employed to distinguish them experimentally from the A-A type. As the charge, energy, and separation distance increase, the additional collapse features merge with the main molecular collapse peaks. We show that the spatial distribution around the vacancy site of the collapse states allows us to differentiate the molecular from the frustrated collapse.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000562320700002 Publication Date 2020-08-25  
  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  
  Notes ; This work was supported by the National Natural Science Foundation of China (Grants No. 61874038 and No. 61704040), National Key R&D Program Grant 2018YFE0120000, the scholarship from China Scholarship Council (CSC: 201908330548), and TRANS2DTMD FlagEra project. ; Approved Most recent IF: 3.7; 2020 IF: 3.836  
  Call Number UA @ admin @ c:irua:172065 Serial 6562  
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Author Shayeganfar, F.; Vasu, K.S.; Nair, R.R.; Peeters, F.M.; Neek-Amal, M. url  doi
openurl 
  Title (up) Monolayer alkali and transition-metal monoxides : MgO, CaO, MnO, and NiO Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal  
  Volume 95 Issue 14 Pages 144109  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Two-dimensional crystals with strong interactions between layers has attracted increasing attention in recent years in a variety of fields. In particular, the growth of a single layer of oxide materials (e.g., MgO, CaO, NiO, and MnO) over metallic substrates were found to display different physical properties than their bulk. In this study, we report on the physical properties of a single layer of metallic oxide materials and compare their properties with their bulk and other two-dimensional (2D) crystals. We found that the planar structure of metallic monoxides are unstable whereas the buckled structures are thermodynamically stable. Also, the 2D-MnO and NiO exhibit different magnetic (ferromagnetic) and optical properties than their bulk, whereas band-gap energy and linear stiffness are found to be decreasing from NiO to MgO. Our findings provide insight into oxide thin-film technology applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000399792400001 Publication Date 2017-04-20  
  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 Times cited 21 Open Access  
  Notes Approved no  
  Call Number UA @ admin @ c:irua:152654 Serial 8278  
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Author Yagmurcukardes, M. url  doi
openurl 
  Title (up) Monolayer fluoro-InSe : formation of a thin monolayer via fluorination of InSe Type A1 Journal article
  Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 100 Issue 2 Pages 024108  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract By performing density functional theory-based first-principles calculations, the formation of a thin monolayer structure, namely InSeF, via fluorination of monolayer InSe is predicted. It is shown that strong interaction of F and In atoms leads to the detachment of In-Se layers in monolayer InSe and 1T-like monolayer InSeF structure is formed. Monolayer InSeF is found to be dynamically stable in terms of its phonon band dispersions. In addition, its Raman spectrum is shown to exhibit totally distinctive features as compared to monolayer InSe. The electronic band dispersions reveal that monolayer InSeF is a direct gap semiconductor whose valence and conduction band edges reside at the Gamma point. Moreover, the orientation-dependent linear elastic properties of monolayer InSeF are investigated in terms of the in-plane stiffness and Poisson ratio. It is found that monolayer InSeF displays strong in-plane anisotropy in elastic constants and it is slightly softer material as compared to monolayer InSe. Overall, it is proposed that a thin, direct gap semiconducting monolayer InSeF can be formed by full fluorination of monolayer InSe as a new member of the two-dimensional family.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000477885700003 Publication Date 2019-07-29  
  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  
  Notes ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). This work is supported by the Flemish Science Foundation (FWO-Vl) by a postdoctoral fellowship (M.Y.). ; Approved Most recent IF: 3.836  
  Call Number UA @ admin @ c:irua:161891 Serial 5423  
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Author Ahmadkhani, S.; Alihosseini, M.; Ghasemi, S.; Ahmadabadi, I.; Hassani, N.; Peeters, F.M.; Neek-Amal, M. url  doi
openurl 
  Title (up) Multiband flattening and linear Dirac band structure in graphene with impurities Type A1 Journal article
  Year 2023 Publication Physical review B Abbreviated Journal  
  Volume 107 Issue 7 Pages 075401-75408  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Flat bands in the energy spectrum have attracted a lot of attention in recent years because of their unique properties and promising applications. Special arrangement of impurities on monolayer graphene are proposed to generate multiflat bands in the electronic band structure. In addition to the single midgap states in the spectrum of graphene with low hydrogen density, we found closely spaced bands around the Fermi level with increasing impurity density, which are similar to discrete lines in the spectrum of quantum dots, as well as the unusual Landau-level energy spectrum of graphene in the presence of a strong magnetic field. The presence of flat bands crucially depends on whether or not there are odd or even electrons of H(F) atoms bound to graphene. Interestingly, we found that a fully hydrogenated (fluoridated) of a hexagon of graphene sheet with six hydrogen (fluorine) atoms sitting on top and bottom in consecutive order exhibits Dirac cones in the electronic band structure with a 20% smaller Fermi velocity as compared to the pristine graphene. Functionalizing graphene introduces various C-C bond lengths resulting in nonuniform strains. Such a nonuniform strain may induce a giant pseudomagnetic field in the system, resulting in quantum Hall effect.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000994364500006 Publication Date 2023-02-02  
  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  
  Impact Factor 3.7 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 3.7; 2023 IF: 3.836  
  Call Number UA @ admin @ c:irua:197431 Serial 8822  
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Author Fernández Becerra, V.; Milošević, M.V. url  doi
openurl 
  Title (up) Multichiral ground states in mesoscopic p-wave superconductors Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 94 Pages 184517  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using Ginzburg-Landau formalism, we investigate the effect of confinement on the ground state of mesoscopic chiral p-wave superconductors in the absence of magnetic field. We reveal stable multichiral states with domain walls separating the regions with different chiralities, as well as monochiral states with spontaneous currents flowing along the edges. We show that multichiral states can exhibit identifying signatures in the spatial profile of the magnetic field if those are not screened by edge currents in the case of strong confinement. Such magnetic detection of domain walls in topological superconductors can serve as long-sought evidence of broken time-reversal symmetry. Furthermore, when applying electric current to mesoscopic p-wave samples, we found a hysteretic behavior in the current-voltage characteristic that distinguishes states with and without domain walls, thereby providing another useful hallmark for indirect confirmation of chiral p-wave superconductivity.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000388816700001 Publication Date 2016-11-30  
  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 7 Open Access  
  Notes ; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen), the COST-EU action MP1201, and the MultiSuper network. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:139241 Serial 4456  
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Author Xiao, Y.M.; Xu, W.; Peeters, F.M.; Van Duppen, B. url  doi
openurl 
  Title (up) Multicomponent plasmons in monolayer MoS2 with circularly polarized optical pumping Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 96 Issue 8 Pages 085405  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract By making use of circularly polarized light and electrostatic gating, monolayer molybdenum disulfide (ML – MoS2) can form a platform supporting multiple types of charge carriers. They can be discriminated by their spin, valley index, or whether they are electrons or holes. We investigate the collective properties of those charge carriers and are able to identify distinct plasmon modes. We analyze the corresponding dispersion relation, lifetime, and oscillator strength, and calculate the phase relation between the oscillations in the different components of the plasmon modes. All platforms in ML-MoS2 support a long-wavelength root q plasmon branch at zero kelvins. In addition to this, for an n-component system, n-1 distinct plasmon modes appear as acoustic modes with linear dispersion in the long-wavelength limit. These modes correspond to out-of-phase oscillations in the different fermion liquids and have, although being damped, a relatively long lifetime. Additionally, we also find distinct modes at large wave vectors that are more strongly damped by intraband processes.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000406861600001 Publication Date 2017-08-04  
  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; WoS citing articles  
  Impact Factor 3.836 Times cited 2 Open Access  
  Notes ; Y.M.X. acknowledges financial support from the China Scholarship Council (CSC). B.V.D. is supported by the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. This work was also supported by the National Natural Science Foundation of China (Grants No. 11574319 and No. 11304272), the Ministry of Science and Technology of China (Grant No. 2011YQ130018), the Department of Science and Technology of Yunnan Province, the Applied Basic Research Foundation of Yunnan Province (2013FD003), and the Chinese Academy of Sciences. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:145729 Serial 4745  
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Author Conti, S.; Perali, A.; Peeters, F.M.; Neilson, D. url  doi
openurl 
  Title (up) Multicomponent screening and superfluidity in gapped electron-hole double bilayer graphene with realistic bands Type A1 Journal article
  Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 99 Issue 14 Pages 144517  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Superfluidity has recently been reported in double electron-hole bilayer graphene. The multiband nature of the bilayers is important because of the very small band gaps between conduction and valence bands. The long-range nature of the superfluid pairing interaction means that screening must be fully taken into account. We have carried out a systematic mean-field investigation that includes (i) contributions to screening from both intraband and interband excitations, (ii) the low-energy band structure of bilayer graphene with its small band gap and flattened Mexican-hat-like low-energy bands, (iii) the large density of states at the bottom of the bands, (iv) electron-hole pairing in the multibands, and (v) electron-hole pair transfers between the conduction and valence band condensates. We find that the superfluidity strongly modifies the intraband contributions to the screening, but that the interband contributions are unaffected. Unexpectedly, a net effect of the screening is to suppress Josephson-like pair transfers and to confine the superfluid pairing entirely to the conduction-band condensate even for very small band gaps, making the system behave similarly to a one-band superfluid.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000465160000004 Publication Date 2019-04-18  
  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; WoS citing articles  
  Impact Factor 3.836 Times cited 13 Open Access  
  Notes ; This work was partially supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl) and the Methusalem Foundation. We thank Mohammad Zarenia and Alfredo VargasParedes for useful discussions. ; Approved Most recent IF: 3.836  
  Call Number UA @ admin @ c:irua:159332 Serial 5221  
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Author Zhang, L.-F.; Flammia, L.; Covaci, L.; Perali, A.; Milošević, M.V. url  doi
openurl 
  Title (up) Multifaceted impact of a surface step on superconductivity in atomically thin films Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 96 Issue 10 Pages 104509  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Recent experiments show that an atomic step on the surface of atomically thin metallic films can strongly affect electronic transport. Here we reveal multiple and versatile effects that such a surface step can have on superconductivity in ultrathin films. By solving the Bogoliubov-de Gennes equations self-consistently in this regime, where quantum confinement dominates the emergent physics, we show that the electronic structure is profoundly modified on the two sides of the step, as is the spatial distribution of the superconducting order parameter and its dependence on temperature and electronic gating. Furthermore, the surface step changes nontrivially the transport properties both in the proximity-induced superconducting pair correlations and the Josephson effect, depending on the step height. These results offer a new route to tailor superconducting circuits and design atomically thin heterojunctions made of one same material.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000411076000012 Publication Date 2017-09-18  
  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; WoS citing articles  
  Impact Factor 3.836 Times cited 7 Open Access  
  Notes ; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen), the Special Research Funds of the University of Antwerp (TOPBOF project) and the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001). ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:146750 Serial 4790  
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Author Ghorbanfekr-Kalashami, H.; Neek-Amal, M.; Peeters, F.M. url  doi
openurl 
  Title (up) N-doped graphene : polarization effects and structural properties Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 174112  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The structural and mechanical properties of N-doped graphene (NG) are investigated using reactive force field (ReaxFF) potentials in large-scale molecular dynamics simulations. We found that ripples, which are induced by the dopants, change the roughness of NG, which depends on the number of dopants and their local arrangement. For any doping ratio N/C, the NG becomes ferroelectric with a net dipole moment. The formation energy increases nonlinearly with N/C ratio, while the Young's modulus, tensile strength, and intrinsic strain decrease with the number of dopants. Our results for the structural deformation and the thermoelectricity of the NG sheet are in good agreement with recent experiments and ab initio calculations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000376245900002 Publication Date 2016-05-20  
  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 15 Open Access  
  Notes ; This work was supported by the ESF-Eurographene project CONGRAN, and the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:134148 Serial 4212  
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Author Walter, A.L.; Sahin, H.; Kang, J.; Jeon, K.J.; Bostwick, A.; Horzum, S.; Moreschini, L.; Chang, Y.J.; Peeters, F.M.; Horn, K.; Rotenberg, E.; url  doi
openurl 
  Title (up) New family of graphene-based organic semiconductors : an investigation of photon-induced electronic structure manipulation in half-fluorinated graphene Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 075439  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The application of graphene to electronic and optoelectronic devices is limited by the absence of reliable semiconducting variants of this material. A promising candidate in this respect is graphene oxide, with a band gap on the order of similar to 5 eV, however, this has a finite density of states at the Fermi level. Here, we examine the electronic structure of three variants of half-fluorinated carbon on Sic(0001), i.e., the (6 root 3 x 6 root 3) R30 degrees C/SiC “buffer layer,” graphene on this (6 root 3 x 6 root 3) R30 degrees C/SiC buffer layer, and graphene decoupled from the SiC substrate by hydrogen intercalation. Using angle-resolved photoemission, core level photoemission, and x-ray absorption, we show that the electronic, chemical, and physical structure of all three variants is remarkably similar, exhibiting a large band gap and a vanishing density of states at the Fermi level. These results are explained in terms of first-principles calculations. This material thus appears very suitable for applications, even more so since it is prepared on a processing-friendly substrate. We also investigate two separate UV photon-induced modifications of the electronic structure that transform the insulating samples (6.2-eV band gap) into semiconducting (similar to 2.5-eV band gap) and metallic regions, respectively.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000371398000007 Publication Date 2016-02-29  
  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 5 Open Access  
  Notes ; The Advanced Light Source is supported by the Director, Office of Science, Office of Basic Energy Sciences, of the US Department of Energy under Contract No. DE-AC02-05CH11231. Work in Erlangen was supported by the DFG through SPP 1459 “Graphene” and SFB 953 “Synthetic Carbon Allotropes” and by the ESF through the EURO-Graphene project GraphicRF. A.L.W. acknowledges support from the Max-Planck-Gesellschaft, the Donostia International Physics Centre, and the Centro de Fisica de Materiales in San Sebastian, Spain, and Brookhaven National Laboratory under US Department of Energy, Office of Science, Office of Basic Energy Sciences, Contract No. DE-SC0012704. This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus-Long Marie Curie Fellowship, and J.K. by a FWO Pegasus-Short Marie Curie Fellowship. Y.J.C. acknowledges support from the National Research Foundation of Korea under Grant No. NRF-2014R1A1A1002868. The authors gratefully acknowledge the work of T. Seyller's group at the Institut fur Physik, Technische Universitat Chemnitz, Germany for providing the samples. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:132352 Serial 4213  
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Author Kong, X.; Li, L.; Leenaerts, O.; Liu, X.-J.; Peeters, F.M. url  doi
openurl 
  Title (up) New group-V elemental bilayers : a tunable structure model with four-, six-, and eight-atom rings Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 96 Issue 3 Pages 035123  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Two-dimensional group-V elemental materials have attracted widespread attention due to their nonzero band gap while displaying high electron mobility. Using first-principles calculations, we propose a series of new elemental bilayers with group-V elements (Bi, Sb, As). Our study reveals the dynamical stability of four-, six-, and eight-atom ring structures, demonstrating their possible coexistence in such bilayer systems. The proposed structures for Sb and As are large-gap semiconductors that are potentially interesting for applications in future nanodevices. The Bi structures have nontrivial topological properties with a direct nontrivial band gap. The nontrivial gap is shown to arise from a band inversion at the Brillouin zone center due to the strong intrinsic spin-orbit coupling in Bi atoms. Moreover, we demonstrate the possibility of tuning the properties of these materials by enhancing the ratio of six-atom rings to four-and eight-atom rings, which results in wider nontrivial band gaps and lower formation energies.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000405363900005 Publication Date 2017-07-14  
  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 14 Open Access  
  Notes ; This work is supported by Ministry of Science and Technology of China (MOST) (Grant No. 2016YFA0301604), National Natural Science Foundation of China (NSFC) ( No. 11574008), the Thousand-Young-Talent Program of China, and the Fonds voor Wetenschappelijk Onderzoek (FWO-Vl). The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center), funded by the Research Foundation – Flanders (FWO) and the Flemish Government – department EWI, and the National Supercomputing Center in Tianjin, funded by the Collaborative Innovation Center of Quantum Matter. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:144834 Serial 4721  
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Author Arsoski, V.V.; Grujić, M.M.; Čukarić, N.A.; Tadic, M.Z.; Peeters, F.M. url  doi
openurl 
  Title (up) Normal and skewed phosphorene nanoribbons in combined magnetic and electric fields Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 96 Issue 12 Pages 125434  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The energy spectrum and eigenstates of single-layer black phosphorus nanoribbons in the presence of a perpendicular magnetic field and an in-plane transverse electric field are investigated by means of a tight-binding method, and the effect of different types of edges is examined analytically. A description based on a continuum model is proposed using an expansion of the tight-binding model in the long-wavelength limit. Thewave functions corresponding to the flatband part of the spectrum are obtained analytically and are shown to agree well with the numerical results from the tight-binding method for both narrow (10 nm) and wide (100 nm) nanoribbons. Analytical expressions for the critical magnetic field at which Landau levels are formed and the ranges of wave numbers in the dispersionless flatband segments in the energy spectra are derived. We examine the evolution of the Landau levels when an in-plane lateral electric field is applied, and we determine analytically how the edge states shift withmagnetic field. For wider nanoribbons, the conductance is shown to have a characteristic staircase shape in combined magnetic and electric fields. Some of the stairs in zigzag and skewed armchair nanoribbons originate from edge states that are found in the band gap.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000411572400008 Publication Date 2017-09-25  
  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  
  Notes ; This work was supported by Erasmus+, 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 @ lucian @ c:irua:146738 Serial 4791  
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Author Torun, E.; Sahin, H.; Peeters, F.M. url  doi
openurl 
  Title (up) Optical properties of GaS-Ca(OH)2 bilayer heterostructure Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 93 Issue 93 Pages 075111  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Finding novel atomically thin heterostructures and understanding their characteristic properties are critical for developing better nanoscale optoelectronic devices. In this study, we investigate the electronic and optical properties of a GaS-Ca(OH)(2) heterostructure using first-principle calculations. The band gap of the GaS-Ca(OH)(2) heterostructure is significantly reduced when compared to those of the isolated constituent layers. Our calculations showthat the GaS-Ca(OH)(2) heterostructure is a type-II heterojunction which can be used to separate photoinduced charge carriers where electrons are localized in GaS and holes in the Ca(OH)(2) layer. This leads to spatially indirect excitons which are important for solar energy and optoelectronic applications due to their long lifetime. By solving the Bethe-Salpeter equation on top of a single shot GW calculation (G(0)W(0)), the dielectric function and optical oscillator strength of the constituent monolayers and the heterostructure are obtained. The oscillator strength of the optical transition for the GaS monolayer is an order of magnitude larger than the Ca(OH)(2) monolayer. We also found that the calculated optical spectra of different stacking types of the heterostructure show dissimilarities, although their electronic structures are rather similar. This prediction can be used to determine the stacking type of ultrathin heterostructures.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000369401000001 Publication Date 2016-02-06  
  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 18 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem Foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure), and HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. H.S. is supported by a FWO Pegasus long Marie Curie Fellowship. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:131614 Serial 4220  
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Author Shekarforoush, S.; Jalali, H.; Yagmurcukardes, M.; Milošević, M.V.; Neek-Amal, M. url  doi
openurl 
  Title (up) Optoelectronic properties of confined water in angstrom-scale slits Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 102 Issue 23 Pages 235406  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The optoelectronic properties of confined water form one of the most active research areas in the past few years. Here we present the multiscale methodology to discern the out-of-plane electronic and dipolar dielectric constants (epsilon(el)(perpendicular to) and epsilon(diP)(perpendicular to)) of strongly confined water. We reveal that epsilon(perpendicular to el) and epsilon(diP)(perpendicular to) become comparable for water confined in angstrom-scale channels (with a height of less than 15 angstrom) within graphene (GE) and hexagonal boron nitride (hBN) bilayers. Channel height (h) associated with a minimum in both epsilon(e)(l)(perpendicular to) and epsilon(dip)(perpendicular to) is linked to the formation of the ordered structure of ice for h approximate to (7 -7.5) angstrom. The recently measured total dielectric constant epsilon(T)(perpendicular to) of nanoconfined water [L. Fumagalli et al., Science 360, 1339 (2018)] is corroborated by our results. Furthermore, we evaluate the contribution from the encapsulating membranes to the dielectric properties, as a function of the interlayer spacing, i.e., the height of the confining channel for water. Finally, we conduct analysis of the optical properties of both confined water and GE membranes, and show that the electron energy loss function of confined water strongly differs from that of bulk water.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000595856100004 Publication Date 2020-12-04  
  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; WoS citing articles  
  Impact Factor 3.7 Times cited 1 Open Access  
  Notes ; This work was supported by the Research Foundation – Flanders (FWO). M.Y. gratefully acknowledges his FWO postdoctoral mandate. ; Approved Most recent IF: 3.7; 2020 IF: 3.836  
  Call Number UA @ admin @ c:irua:175051 Serial 6695  
Permanent link to this record
 

 
Author Sankaran, K.; Swerts, J.; Couet, S.; Stokbro, K.; Pourtois, G. url  doi
openurl 
  Title (up) Oscillatory behavior of the tunnel magnetoresistance due to thickness variations in Ta vertical bar CoFe vertical bar MgO magnetic tunnel junctions : a first-principles study Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 94 Pages 094424  
  Keywords A1 Journal article; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)  
  Abstract To investigate the impact of both the CoFe ferromagnetic layer thickness and the capping paramagnetic layer on the tunnel magnetoresistance (TMR), we performed first-principles simulations on epitaxial magnetic tunnel junctions contacted with either CoFe or Ta paramagnetic capping layers. We observed a strong oscillation of the TMR amplitude with respect to the thickness of the ferromagnetic layer. The TMR is found to be amplified whenever the MgO spin tunnel barrier is thickened. Quantization of the electronic structure of the ferromagnetic layers is found to be at the origin of this oscillatory behavior. Metals such as Ta contacting the magnetic layer are found to enhance the amplitude of the oscillations due to the occurrence of an interface dipole. The latter drives the band alignment and tunes the nature of the spin channels that are active during the tunneling process. Subsequently, the regular transmission spin channels are modulated in the magnetic tunnel junction stack and other complex ones are being activated.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000383860700004 Publication Date 2016-09-20  
  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 4 Open Access  
  Notes Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:137122 Serial 4468  
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Author Stosic, D.; Mulkers, J.; Van Waeyenberge, B.; Ludermir, T.B.; Milošević, M.V. url  doi
openurl 
  Title (up) 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 Zhao, H.J.; Misko, V.R.; Tempere, J.; Nori, F. url  doi
openurl 
  Title (up) Pattern formation in vortex matter with pinning and frustrated intervortex interactions Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 95 Issue 95 Pages 104519  
  Keywords A1 Journal article; Theory of quantum systems and complex systems; Condensed Matter Theory (CMT)  
  Abstract We investigate the effects related to vortex-core deformations when vortices approach each other. As a result of these vortex-core deformations, the vortex-vortex interaction effectively acquires an attractive component leading to a variety of vortex patterns typical for systems with nonmonotonic repulsive-attractive interaction, such as stripes and labyrinths. The core deformations are anisotropic and can induce frustration in the vortex-vortex interaction. In turn, this frustration has an impact on the resulting vortex patterns, which are analyzed in the presence of additional random pinning, as a function of the pinning strength. This analysis can be applicable to vortices in multiband superconductors or to vortices in Bose-Einstein condensates.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000399138800006 Publication Date 2017-03-30  
  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 3.836 Times cited 5 Open Access  
  Notes ; We acknowledge fruitful discussions with E. Babaev and V. Gladilin. This work is partially supported by the Natural Science Foundation of Jiangsu Province (Grant No. BK20150595), the National Natural Science Foundation of China (Grants No. NSFC-U1432135, No. 11611140101, and No. 11674054), the “Odysseus” program of the Flemish Government and Flemish Research Foundation (FWO-Vl), the Flemish Research Foundation (through Projects No. G.0115.12N, No. G.0119.12N, No. G.0122.12N, and No. G.0429.15N), the Research Fund of the University of Antwerp, the RIKEN iTHES Project, the MURI Center for Dynamic Magneto-Optics via the AFOSR Award No. FA9550-14-1-0040, the IMPACT program of JST, a Grant-in-Aid for Scientific Research (A), the Japan Society for the Promotion of Science (KAKENHI), CREST, and a grant from the John Templeton Foundation. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:142429 Serial 4602  
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Author Khoeini, F.; Shakouri; Peeters, F.M. url  doi
openurl 
  Title (up) Peculiar half-metallic state in zigzag nanoribbons of MoS2 : spin filtering Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 94 Pages 125412  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Layered structures of molybdenum disulfide (MoS2) belong to a new class of two-dimensional (2D) semiconductor materials in which monolayers exhibit a direct band gap in their electronic spectrum. This band gap has recently been shown to vanish due to the presence of metallic edge modes when MoS2 monolayers are terminated by zigzag edges on both sides. Here, we demonstrate that a zigzag nanoribbon of MoS2, when exposed to an external exchange field in combination with a transverse electric field, has the potential to exhibit a peculiar half-metallic nature and thereby allows electrons of only one spin direction to move. The peculiarity of such spin-selective conductors originates from a spin switch near the gap-closing region, so the allowed spin orientation can be controlled by means of an external gate voltage. It is shown that the induced half-metallic phase is resistant to random fluctuations of the exchange field as well as the presence of edge vacancies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000383238800009 Publication Date 2016-09-09  
  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 ; ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:137130 Serial 4360  
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Author Heshmati-Moulai, A.; Simchi, H.; Esmaeilzadeh, M.; Peeters, F.M. url  doi
openurl 
  Title (up) Phase transition and spin-resolved transport in MoS2 nanoribbons Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 94 Pages 235424  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The electronic structure and transport properties of monolayer MoS2 are studied using a tight-binding approach coupled with the nonequilibrium Green's function method. A zigzag nanoribbon of MoS2 is conducting due to the intersection of the edge states with the Fermi level that is located within the bulk gap. We show that applying a transverse electric field results in the disappearance of this intersection and turns the material into a semiconductor. By increasing the electric field the band gap undergoes a two stage linear increase after which it decreases and ultimately closes. It is shown that in the presence of a uniform exchange field, this electric field tuning of the gap can be exploited to open low energy domains where only one of the spin states contributes to the electronic conductance. This introduces possibilities in designing spin filters for spintronic applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000394546100005 Publication Date 2016-12-20  
  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 7 Open Access  
  Notes ; ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:141978 Serial 4557  
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Author Scuracchio, P.; Michel, K.H.; Peeters, F.M. doi  openurl
  Title (up) Phonon hydrodynamics, thermal conductivity, and second sound in two-dimensional crystals Type A1 Journal article
  Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 99 Issue 14 Pages 144303  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Starting from our previous work in which we obtained a system of coupled integrodifferential equations for acoustic sound waves and phonon density fluctuations in two-dimensional (2D) crystals, we derive here the corresponding hydrodynamic equations, and we study their consequences as a function of temperature and frequency. These phenomena encompass propagation and damping of acoustic sound waves, diffusive heat conduction, second sound, and Poiseuille heat flow, all of which are characterized by specific transport coefficients. We calculate these coefficients by means of correlation functions without using the concept of relaxation time. Numerical calculations are performed as well in order to show the temperature dependence of the transport coefficients and of the thermal conductivity. As a consequence of thermal tension, mechanical and thermal phenomena are coupled. We calculate the dynamic susceptibilities for displacement and temperature fluctuations and study their resonances. Due to the thermomechanical coupling, the thermal resonances such as the Landau-Placzek peak and the second-sound doublet appear in the displacement susceptibility, and conversely the acoustic sound wave doublet appears in the temperature susceptibility, Our analytical results not only apply to graphene, but they are also valid for arbitrary 2D crystals with hexagonal symmetry, such as 2D hexagonal boron nitride, 2H-transition-metal dichalcogenides, and oxides.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000464717300006 Publication Date 2019-04-10  
  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 13 Open Access  
  Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836  
  Call Number UA @ admin @ c:irua:159346 Serial 5225  
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Author Bekaert, J. pdf  doi
openurl 
  Title (up) Phonon-mediated superconductivity in ternary silicides X₄ CoSi (X = Nb, Ta) Type A1 Journal article
  Year 2023 Publication Physical review B Abbreviated Journal  
  Volume 108 Issue 13 Pages 134504-134507  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The superconducting properties of two recently synthesized ternary silicides with unit formula X<sub>4</sub>CoSi (X = Nb, Ta) are investigated through ab initio calculations combined with Eliashberg theory. Interestingly, their crystal structure comprises interlocking honeycomb networks of Nb/Ta atoms. Nb<sub>4</sub>CoSi is found to harbor better conditions for phonon-mediated superconductivity, as it possesses a higher density of states at the Fermi level, fostering stronger electron-phonon coupling. The superconducting critical temperatures (T<sub>c</sub>) follow the same trend, with Nb<sub>4</sub>CoSi having a twice higher value than Ta<sub>4</sub>CoSi. Furthermore, the calculated T<sub>c</sub> values (5.9 K vs 3.1 K) agree excellently with the experimentally obtained ones, establishing superconductivity in this new materials class as mediated by the electron-phonon coupling. Furthermore, my calculations show that the superconducting properties of these compounds do not simply correlate with the parameters of their honeycomb networks, contrary to proposals raised in the literature. Rather, their complete fermiology and phonon spectrum should be taken into account in order to explain their respective superconducting properties.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 001140080300003 Publication Date 2023-10-17  
  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:201445 Serial 9071  
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Author Michel, K.H.; Çakir, D.; Sevik, C.; Peeters, F.M. url  doi
openurl 
  Title (up) Piezoelectricity in two-dimensional materials : comparative study between lattice dynamics and ab initio calculations Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 95 Issue 95 Pages 125415  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The elastic constant C-11 and piezoelectric stress constant e(1),(11) of two-dimensional (2D) dielectric materials comprising h-BN, 2H-MoS2, and other transition-metal dichalcogenides and dioxides are calculated using lattice dynamical theory. The results are compared with corresponding quantities obtained with ab initio calculations. We identify the difference between clamped-ion and relaxed-ion contributions with the dependence on inner strains which are due to the relative displacements of the ions in the unit cell. Lattice dynamics allows us to express the inner-strain contributions in terms of microscopic quantities such as effective ionic charges and optoacoustical couplings, which allows us to clarify differences in the piezoelectric behavior between h-BN and MoS2. Trends in the different microscopic quantities as functions of atomic composition are discussed.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000396013400005 Publication Date 2017-03-11  
  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; WoS citing articles  
  Impact Factor 3.836 Times cited 29 Open Access  
  Notes ; The authors acknowledge useful discussions with L. Wirtz and A. Molina-Sanchez. This work was supported by the Methusalem program and the Fonds voor Wetenschappelijk Onderzoek-Vlaanderen. Computational resources were provided by HPC infrastructure of the University of Antwerp (CalcUA), a division of the Flemish Supercomputer Center (VSC), which is funded by the Hercules foundation. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:142444 Serial 4603  
Permanent link to this record
 

 
Author Stosic, D.; Ludermir, T.B.; Milošević, M.V. url  doi
openurl 
  Title (up) Pinning of magnetic skyrmions in a monolayer Co film on Pt(111) : Theoretical characterization and exemplified utilization Type A1 Journal article
  Year 2017 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 96 Issue 21 Pages 214403  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract <script type='text/javascript'>document.write(unpmarked('Magnetic skyrmions are nanoscale windings of the spin structure that can be observed in chiral magnets and hold promise for potential applications in storing or processing information. Pinning due to ever-present material imperfections crucially affects the mobility of skyrmions. Therefore, a proper understanding of how magnetic skyrmions pin to defects is necessary for the development and performance of spintronic devices. Here we present a fundamental analysis on the interactions of single skyrmions with atomic defects of distinctly different origins, in a Co monolayer on Pt, based on minimum-energy paths considerations and atomic-spin simulations. We first report the preferred pinning loci of the skyrmion as a function of its nominal size and the type of defect being considered, to further reveal the manipulation and \u0022breathing\u0022 of skyrmion core in the vicinity of a defect. We also show the behavior of skyrmions in the presence of an extended defect of particular geometry, that can lead to ratcheted skyrmion motion or a facilitated guidance on a defect \u0022trail.\u0022 We close the study with reflections on the expected thermal stability of the skyrmion against collapse on itself for a given nature of the defect, and discuss the applications where control of skyrmions by defects is of particular interest.'));  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000416846900002 Publication Date 2017-12-01  
  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 52 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 UA @ lucian @ c:irua:147684 Serial 4890  
Permanent link to this record
 

 
Author Callewaert, V.; Shastry, K.; Saniz, R.; Makkonen, I.; Barbiellini, B.; Assaf, B.A.; Heiman, D.; Moodera, J.S.; Partoens, B.; Bansil, A.; Weiss, A.H.; url  doi
openurl 
  Title (up) Positron surface state as a spectroscopic probe for characterizing surfaces of topological insulator materials Type A1 Journal article
  Year 2016 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 94 Issue 94 Pages 115411  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Topological insulators are attracting considerable interest due to their potential for technological applications and as platforms for exploring wide-ranging fundamental science questions. In order to exploit, fine-tune, control, and manipulate the topological surface states, spectroscopic tools which can effectively probe their properties are of key importance. Here, we demonstrate that positrons provide a sensitive probe for topological states and that the associated annihilation spectrum provides a technique for characterizing these states. Firm experimental evidence for the existence of a positron surface state near Bi2Te2Se with a binding energy of E-b = 2.7 +/- 0.2 eV is presented and is confirmed by first-principles calculations. Additionally, the simulations predict a significant signal originating from annihilation with the topological surface states and show the feasibility to detect their spin texture through the use of spin-polarized positron beams.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000383232800012 Publication Date 2016-09-06  
  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 15 Open Access  
  Notes ; I.M. acknowledges discussions with M. Ervasti and A. Harju. V.C. and R.S. were supported by the FWO-Vlaanderen through Project No. G. 0224.14N. The computational resources and services used in this paper were, in part, provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the Hercules Foundation and the Flemish Government (EWI Department). I.M. acknowledges financial support from the Academy of Finland (Projects No. 285809 and No. 293932). The work at Northeastern University was supported by the U.S. Department of Energy (DOE), Office of Science, Basic Energy Sciences Grant No. DE-FG02-07ER46352 and benefited from Northeastern University's Advanced Scientific Computation Center (ASCC) and the NERSC supercomputing center through DOE Grant No. DE-AC02-05CH11231. K.S. and A.W. acknowledge financial support from the National Science Foundation through Grants No. DMR-MRI-1338130 and No. DMR-1508719. D.H. received financial support from the National Science Foundation (Grant No. ECCS-1402738). J.S.M. was supported by the STC Center for Integrated Quantum Materials under NSF Grants No. DMR-1231319, No. DMR-1207469, and ONR Grant No. N00014-13-1-0301. B.A.A. also acknowledges support from the LabEx ENS-ICFP Grant No. ANR-10-LABX-0010/ANR-10-IDEX-0001-02 PSL. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:137134 Serial 4362  
Permanent link to this record
 

 
Author Yagmurcukardes, M.; Mogulkoc, Y.; Akgenc, B.; Mogulkoc, A.; Peeters, F.M. doi  openurl
  Title (up) 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 Plumadore, R.; Baskurt, M.; Boddison-Chouinard, J.; Lopinski, G.; Modarresi, M.; Potasz, P.; Hawrylak, P.; Sahin, H.; Peeters, F.M.; Luican-Mayer, A. url  doi
openurl 
  Title (up) Prevalence of oxygen defects in an in-plane anisotropic transition metal dichalcogenide Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 102 Issue 20 Pages 205408  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Atomic scale defects in semiconductors enable their technological applications and realization of different quantum states. Using scanning tunneling microscopy and spectroscopy complemented by ab initio calculations we determine the nature of defects in the anisotropic van der Waals layered semiconductor ReS2. We demonstrate the in-plane anisotropy of the lattice by directly visualizing chains of rhenium atoms forming diamond-shaped clusters. Using scanning tunneling spectroscopy we measure the semiconducting gap in the density of states. We reveal the presence of lattice defects and by comparison of their topographic and spectroscopic signatures with ab initio calculations we determine their origin as oxygen atoms absorbed at lattice point defect sites. These results provide an atomic-scale view into the semiconducting transition metal dichalcogenides, paving the way toward understanding and engineering their properties.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000587595800007 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 6 Open Access  
  Notes ; The authors acknowledge funding from National Sciences and Engineering Research Council (NSERC) Discovery Grant No. RGPIN-2016-06717. We also acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) through QC2DM Strategic Project No. STPGP 521420. P.H. thanks uOttawa Research Chair in Quantum Theory of Materials for support. P.P. acknowledges partial financial support from National Science Center (NCN), Poland, Grant Maestro No. 2014/14/A/ST3/00654, and calculations were performed in theWroclaw Center for Networking and Supercomputing. H.S. acknowledges financial support from TUBITAK under Project No. 117F095 and from Turkish Academy of Sciences under the GEBIP program. Our computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid eInfrastructure). ; Approved Most recent IF: 3.7; 2020 IF: 3.836  
  Call Number UA @ admin @ c:irua:173525 Serial 6584  
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Author Mijin, S.D.; Baum, A.; Bekaert, J.; Solajic, A.; Pesic, J.; Liu, Y.; He, G.; Milošević, M.V.; Petrovic, C.; Popovic, Z., V; Hackl, R.; Lazarevic, N. url  doi
openurl 
  Title (up) Probing charge density wave phases and the Mott transition in 1T-TaS₂I by inelastic light scattering Type A1 Journal article
  Year 2021 Publication Physical Review B Abbreviated Journal Phys Rev B  
  Volume 103 Issue 24 Pages 245133  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present a polarization-resolved, high-resolution Raman scattering study of the three consecutive charge density wave (CDW) regimes in 1T-TaS2 single crystals, supported by ab initio calculations. Our analysis of the spectra within the low-temperature commensurate (C-CDW) regime shows P (3) over bar symmetry of the system, thus excluding the previously proposed triclinic stacking of the “star-of-David” structure, and promoting trigonal or hexagonal stacking instead. The spectra of the high-temperature incommensurate (IC-CDW) phase directly project the phonon density of states due to the breaking of the translational invariance, supplemented by sizable electron-phonon coupling. Between 200 and 352 K, our Raman spectra show contributions from both the IC-CDW and the C-CDW phases, indicating their coexistence in the so-called nearly commensurate (NC-CDW) phase. The temperature dependence of the symmetry-resolved Raman conductivity indicates the stepwise reduction of the density of states in the CDW phases, followed by a Mott transition within the C-CDW phase. We determine the size of the Mott gap to be Omega(gap) approximate to 170-190 meV, and track its temperature dependence.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000664450500002 Publication Date 2021-06-22  
  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 OpenAccess  
  Notes Approved Most recent IF: 3.836  
  Call Number UA @ admin @ c:irua:179664 Serial 7015  
Permanent link to this record
 

 
Author Covaci, L.; Marsiglio, F. doi  openurl
  Title (up) 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 Bercx, M.; Partoens, B.; Lamoen, D. pdf  url
doi  openurl
  Title (up) Quantitative modeling of secondary electron emission from slow-ion bombardment on semiconductors Type A1 Journal article
  Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 99 Issue 8 Pages 085413  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract When slow ions incident on a surface are neutralized, the excess potential energy is passed on to an electron inside the surface, leading to emission of secondary electrons. The microscopic description of this process, as

well as the calculation of the secondary electron yield, is a challenging problem due to its complexity as well

as its sensitivity to surface properties. One of the first quantitative descriptions was articulated in the 1950s by

Hagstrum, who based his calculation on a parametrization of the density of states of the material. In this paper, we

present a model for calculating the secondary electron yield, derived from Hagstrum’s initial approach. We use

first-principles density functional theory calculations to acquire the necessary input and introduce the concept of

electron cascades to Hagstrum’s model in order to improve the calculated spectra, as well as remove its reliance

on fitting parameters. We apply our model to He+ and Ne+ ions incident on Ge(111) and Si(111) and obtain

yield spectra that match closely to the experimental results of Hagstrum.
 
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000458367800010 Publication Date 2019-02-11  
  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 5 Open Access OpenAccess  
  Notes We would like to thank Prof. D. Depla for the useful discussions on the secondary electron yield. Furthermore, we acknowledge financial support of FWO-Vlaanderen through project G.0216.14N. The computational resources and services used in this work were provided by the VSC (Flemish Supercomputer Center) and the HPC infrastructure of the University of Antwerp (CalcUA), both funded by the FWOVlaanderen and the Flemish Government-department EWI. Approved Most recent IF: 3.836  
  Call Number EMAT @ emat @UA @ admin @ c:irua:157174 Serial 5154  
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