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| Author | Sisakht, E.T.; Fazileh, F.; Zare, M.H.; Zarenia, M.; Peeters, F.M. | ||||
| Title | Strain-induced topological phase transition in phosphorene and in phosphorene nanoribbons | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 94 | Issue  |
94 | Pages | 085417 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Using the tight-binding (TB) approximation with inclusion of the spin-orbit interaction, we predict a topological phase transition in the electronic band structure of phosphorene in the presence of axial strains. We derive a low-energy TB Hamiltonian that includes the spin-orbit interaction for bulk phosphorene. Applying a compressive biaxial in-plane strain and perpendicular tensile strain in ranges where the structure is still stable leads to a topological phase transition. We also examine the influence of strain on zigzag phosphorene nanoribbons (zPNRs) and the formation of the corresponding protected edge states when the system is in the topological phase. For zPNRs up to a width of 100 nm the energy gap is at least three orders of magnitude larger than the thermal energy at room temperature. | ||||
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| Language | Wos | 000381600800004 | Publication Date | 2016-08-18 | |
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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 | 76 | Open Access | |
| Notes | ; This work was supported by Ministry of Science, Research and Technology, Iran. M.Z. acknowledges support as a postdoctoral fellow of the Flemish Research Foundation (FWO-Vl). ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:135643 | Serial | 4309 | ||
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| Author | Juchtmans, R.; Guzzinati, G.; Verbeeck, J. | ||||
| Title | Extension of Friedel's law to vortex-beam diffraction | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical Review A | Abbreviated Journal | Phys Rev A |
| Volume | 94 | Issue |
94 | Pages | 033858 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | Friedel's law states that the modulus of the Fourier transform of real functions is centrosymmetric, while the phase is antisymmetric. As a consequence of this, elastic scattering of plane-wave photons or electrons within the first-order Born-approximation, as well as Fraunhofer diffraction on any aperture, is bound to result in centrosymmetric diffraction patterns. Friedel's law, however, does not apply for vortex beams, and centrosymmetry in general is not present in their diffraction patterns. In this work we extend Friedel's law for vortex beams by showing that the diffraction patterns of vortex beams with opposite topological charge, scattered on the same two-dimensional potential, always are centrosymmetric to one another, regardless of the symmetry of the scattering object. We verify our statement by means of numerical simulations and experimental data. Our research provides deeper understanding in vortex-beam diffraction and can be used to design new experiments to measure the topological charge of vortex beams with diffraction gratings or to study general vortex-beam diffraction. | ||||
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| Language | Wos | 000384374500010 | Publication Date | 2016-09-30 | |
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| ISSN | 2469-9926 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.925 | Times cited | 13 | Open Access | |
| Notes | The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2 and ERC Starting Grant No. 278510 VORTEX.; ECASJO_; | Approved | Most recent IF: 2.925 | ||
| Call Number | EMAT @ emat @ c:irua:137200UA @ admin @ c:irua:137200 | Serial | 4314 | ||
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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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| Language | Wos | 000385622500009 | Publication Date | 2016-10-12 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
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| 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 | 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 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
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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 | 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 | Mirzakhani, M.; Zarenia, M.; da Costa, D.R.; Ketabi, S.A.; Peeters, F.M. | ||||
| Title | Energy levels of ABC-stacked trilayer graphene quantum dots with infinite-mass boundary conditions | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 94 | Issue |
94 | Pages | 165423 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Using the continuum model, we investigate the confined states and the corresponding wave functions of ABC-stacked trilayer graphene (TLG) quantum dots (QDs). First, a general infinite-mass boundary condition is derived and applied to calculate the electron and hole energy levels of a circular QD in both the absence and presence of a perpendicular magnetic field. Our analytical results for the energy spectra agree with those obtained by using the tight-binding model, where a TLG QD is surrounded by a staggered potential. Our findings show that (i) the energy spectrum exhibits intervalley symmetry E-K(e)(m) = -E-K'(h)(m) for the electron (e) and hole (h) states, where m is the angular momentum quantum number, (ii) the zero-energy Landau level (LL) is formed by the magnetic states with m <= 0 for both Dirac valleys, that is different from monolayer and bilayer graphene QD with infinite-mass potential in which only one of the cones contributes, and (iii) groups of three quantum Hall edge states in the tight-binding magnetic spectrum approach the zero LL, which results from the layer symmetry in TLG QDs. | ||||
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| Language | Wos | 000386168000011 | Publication Date | 2016-10-19 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
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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 | 9 | Open Access | |
| Notes | ; This work was supported by the Flemish Science Foundation (FWO-Vl), the Brazilian Council for Research (CNPq), the Science without Borders program, PRONEX/FUNCAP, and CAPES foundation. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:138174 | Serial | 4353 | ||
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| Author | Xiao, Y.M.; Xu, W.; Van Duppen, B.; Peeters, F.M. | ||||
| Title | Infrared to terahertz optical conductivity of n-type and p-type monolayer MoS2 in the presence of Rashba spin-orbit coupling | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 94 | Issue |
94 | Pages | 155432 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We investigate the effect of Rashba spin-orbit coupling (SOC) on the optoelectronic properties of n- and p-type monolayer MoS2. The optical conductivity is calculated within the Kubo formalism. We find that the spin-flip transitions enabled by the Rashba SOC result in a wide absorption window in the optical spectrum. Furthermore, we evaluate the effects of the polarization direction of the radiation, temperature, carrier density, and the strength of the Rashba spin-orbit parameter on the optical conductivity. We find that the position, width, and shape of the absorption peak or absorption window can be tuned by varying these parameters. This study shows that monolayer MoS2 can be a promising tunable optical and optoelectronic material that is active in the infrared to terahertz spectral range. | ||||
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| Language | Wos | 000386097800003 | Publication Date | 2016-10-18 | |
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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 | 20 | Open Access | |
| Notes | ; Y.M.X. acknowledges financial support from the China Scholarship Council (CSC). This work was also supported by the National Natural Science Foundation of China (Grant No. 11574319), Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. B.V.D. is supported by a Ph.D. fellowship from the Flemish Science Foundation. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:138175 | Serial | 4355 | ||
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| Author | Yagmurcukardes, M.; Senger, R.T.; Peeters, F.M.; Sahin, H. | ||||
| Title | Mechanical properties of monolayer GaS and GaSe crystals | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 94 | Issue |
94 | Pages | 245407 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | The mechanical properties of monolayer GaS and GaSe crystals are investigated in terms of their elastic constants: in-plane stiffness (C), Poisson ratio (nu), and ultimate strength (sigma(U)) by means of first-principles calculations. The calculated elastic constants are compared with those of graphene and monolayer MoS2. Our results indicate that monolayer GaS is a stiffer material than monolayer GaSe crystals due to the more ionic character of the Ga-S bonds than the Ga-Se bonds. Although their Poisson ratio values are very close to each other, 0.26 and 0.25 for GaS and GaSe, respectively, monolayer GaS is a stronger material than monolayer GaSe due to its slightly higher sU value. However, GaS and GaSe crystals are found to be more ductile and flexible materials than graphene and MoS2. We have also analyzed the band-gap response of GaS and GaSe monolayers to biaxial tensile strain and predicted a semiconductor-metal crossover after 17% and 14% applied strain, respectively, for monolayer GaS and GaSe. In addition, we investigated how the mechanical properties are affected by charging. We found that the flexibility of single layer GaS and GaSe displays a sharp increase under 0.1e/cell charging due to the repulsive interactions between extra charges located on chalcogen atoms. These charging-controllable mechanical properties of single layers of GaS and GaSe can be of potential use for electromechanical applications. | ||||
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| Language | Wos | 000389503400008 | Publication Date | 2016-12-05 | |
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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 | 108 | Open Access | |
| Notes | ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP program. R.T.S. acknowledges the support from TUBITAK through project 114F397. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:139229 | Serial | 4356 | ||
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| Author | Khoeini, F.; Shakouri; Peeters, F.M. | ||||
| Title | 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. | ||||
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| Language | Wos | 000383238800009 | Publication Date | 2016-09-09 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
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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 | 38 | Open Access | |
| Notes | ; ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:137130 | Serial | 4360 | ||
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| 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.; | ||||
| Title | 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. | ||||
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| Language | Wos | 000383232800012 | Publication Date | 2016-09-06 | |
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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 | 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 | ||
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| Author | Yagmurcukardes, M.; Torun, E.; Senger, R.T.; Peeters, F.M.; Sahin, H. | ||||
| Title | 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. | ||||
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| Language | Wos | 000386769400007 | Publication Date | 2016-11-03 | |
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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 | 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 | Shumilin, A.V.; Baranov, V.V.; Kabanov, V.V. | ||||
| Title | Upper critical field in the model with finite-range interaction between electrons | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 94 | Issue |
94 | Pages | 174506 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | We develop a theory of the upper critical field in a BCS superconductor with a nonlocal interaction between electrons. We have shown that the nonlocal interaction is characterized by the parameter k(F)rho(0), where k(F) is the Fermi momentum and rho(0) is the radius of electron-electron interaction. The presence of the external magnetic field leads to the generation of additional components of the order parameter with different angular momenta. This effect leads to the enhancement of the upper critical field above the orbital limiting field. In addition the upward curvature in the temperature dependence of H-c2 (T) in the clean limit is predicted. The impurity scattering suppresses the effect in the dirty limit. | ||||
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| Language | Wos | 000387884100005 | Publication Date | 2016-11-14 | |
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| ISSN | 2469-9950;2469-9969; | ISBN | Additional Links | UA library record; WoS full record | |
| Impact Factor | 3.836 | Times cited | Open Access | ||
| Notes | ; ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:139166 | Serial | 4365 | ||
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| Author | Juchtmans, R.; Clark, L.; Lubk, A.; Verbeeck, J. | ||||
| Title | Spiral phase plate contrast in optical and electron microscopy | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review A | Abbreviated Journal | Phys Rev A |
| Volume | 94 | Issue |
94 | Pages | 023838 |
| Keywords | A1 Journal article; Electron microscopy for materials research (EMAT) | ||||
| Abstract | The use of phase plates in the back focal plane of a microscope is a well-established technique in optical microscopy to increase the contrast of weakly interacting samples and is gaining interest in electron microscopy as well. In this paper we study the spiral phase plate (SPP), also called helical, vortex, or two-dimensional Hilbert phase plate, which adds an angularly dependent phase of the form exp(iℓϕk) to the exit wave in Fourier space. In the limit of large collection angles, we analytically calculate that the average of a pair of l=+-1 SPP filtered images is directly proportional to the gradient squared of the exit wave, explaining the edge contrast previously seen in optical SPP work. We discuss the difference between a clockwise-anticlockwise pair of SPP filtered images and derive conditions under which the modulus of the wave's gradient can be seen directly from one SPP filtered image. This work provides the theoretical background to interpret images obtained with a SPP, thereby opening new perspectives for new experiments to study, for example, magnetic materials in an electron microscope. |
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| Language | Wos | 000381882800011 | Publication Date | 2016-08-22 | |
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| ISSN | 2469-9926 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 2.925 | Times cited | 10 | Open Access | |
| Notes | The authors acknowledge support from the FWO (Aspirant Fonds Wetenschappelijk Onderzoek – Vlaanderen) and the EU under the Seventh Framework Program (FP7) under a contract for an Integrated Infrastructure Initiative, Reference No. 312483-ESTEEM2 and ERC Starting Grant No. 278510 VORTEX.; ECASJO_ | Approved | Most recent IF: 2.925 | ||
| Call Number | EMAT @ emat @ c:irua:140086 | Serial | 4418 | ||
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| Author | Fernández Becerra, V.; Milošević, M.V. | ||||
| Title | 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. | ||||
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| Language | Wos | 000388816700001 | Publication Date | 2016-11-30 | |
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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 | 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 | Petrovic, M.D.; Peeters, F.M. | ||||
| Title | Quantum transport in graphene Hall bars: Effects of vacancy disorder | Type | A1 Journal article | ||
| Year | 2016 | Publication | Physical review B | Abbreviated Journal | Phys Rev B |
| Volume | 94 | Issue |
94 | Pages | 235413 |
| Keywords | A1 Journal article; Condensed Matter Theory (CMT) | ||||
| Abstract | Using the tight-binding model, we investigate the influence of vacancy disorder on electrical transport in graphene Hall bars in the presence of quantizing magnetic fields. Disorder, induced by a random distribution of monovacancies, breaks the graphene sublattice symmetry and creates states localized on the vacancies. These states are observable in the bend resistance, as well as in the total DOS. Their energy is proportional to the square root of the magnetic field, while their localization length is proportional to the cyclotron radius. At the energies of these localized states, the electron current flows around the monovacancies and, as we show, it can follow unexpected paths depending on the particular arrangement of vacancies. We study how these localized states change with the vacancy concentration, and what are the effects of including the next-nearest-neighbor hopping term. Our results are also compared with the situation when double vacancies are present in the system. Double vacancies also induce localized states, but their energy and magnetic field dependencies are different. Their localization energy scales linearly with the magnetic field, and their localization length appears not to depend on the field strength. | ||||
| Address | |||||
| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000389574200005 | Publication Date | 2016-12-14 | |
| 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 | 14 | Open Access | |
| Notes | ; This work was supported by the Methusalem program of the Flemish government. ; | Approved | Most recent IF: 3.836 | ||
| Call Number | UA @ lucian @ c:irua:140237 | Serial | 4459 | ||
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| Author | Sankaran, K.; Swerts, J.; Couet, S.; Stokbro, K.; Pourtois, G. | ||||
| Title | 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 | Heshmati-Moulai, A.; Simchi, H.; Esmaeilzadeh, M.; Peeters, F.M. | ||||
| Title | 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 | Horzum, S.; Torun, E.; Serin, T.; Peeters, F.M. | ||||
| Title | Structural, electronic and optical properties of Cu-doped ZnO : experimental and theoretical investigation | Type | A1 Journal article | ||
| Year | 2016 | Publication | Philosophical magazine | Abbreviated Journal | Philos Mag |
| Volume | 96 | Issue |
96 | Pages | 1743-1756 |
| Keywords | A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT) | ||||
| Abstract | Experiments are supplemented with ab initio density functional theory (DFT) calculations in order to investigate how the structural, electronic and optical properties of zinc oxide (ZnO) thin films are modified upon Cu doping. Changes in characteristic properties of doped thin films, that are deposited on a glass substrate by sol-gel dip coating technique, are monitored using X-ray diffraction (XRD) and UV measurements. Our ab initio calculations show that the electronic structure of ZnO can be well described by DFT+U/G(0)W(0) method and we find that Cu atom substitutional doping in ZnO is the most favourable case. Our XRD measurements reveal that the crystallite size of the films decrease with increasing Cu doping. Moreover, we determine the optical constants such as refractive index, extinction coefficient, optical dielectric function and optical energy band gap values of the films by means of UV-Vis transmittance spectra. The optical band gap of ZnO the thin film linearly decreases from 3.25 to 3.20 eV at 5% doping. In addition, our calculations reveal that the electronic defect states that stem from Cu atoms are not optically active and the optical band gap is determined by the ZnO band edges. Experimentally observed structural and optical results are in good agreement with our theoretical results. | ||||
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| Corporate Author | Thesis | ||||
| Publisher | Place of Publication | Editor | |||
| Language | Wos | 000376076500002 | Publication Date | 2016-05-07 | |
| Series Editor | Series Title | Abbreviated Series Title | |||
| Series Volume | Series Issue | Edition | |||
| ISSN | 1478-6435 | ISBN | Additional Links | UA library record; WoS full record; WoS citing articles | |
| Impact Factor | 1.505 | Times cited | 29 | Open Access | |
| Notes | ; Theoretical part of 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. Experimental part of this work was supported by Ankara University BAP under Project Number [14B0443001]. ; | Approved | Most recent IF: 1.505 | ||
| Call Number | UA @ lucian @ c:irua:134161 | Serial | 4254 | ||
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