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Author Wang, W.; Van Duppen, B.; Peeters, F.M.
Title Intense-terahertz-laser-modulated magnetopolaron effect on shallow-donor states in the presence of magnetic field in the Voigt configuration Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 1 Pages 014114
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The laser-modulated magnetopolaron effect on shallow donors in semiconductors is investigated in the presence of a magnetic field in the Voigt configuration. A nonperturbative approach is used to describe the electron-photon interaction by including the radiation field in an exact way via a laser-dressed interaction potential. Through a variational approach we evaluate the donor binding energy. We find that the interaction strength of the laser-dressed Coulomb potential in the z direction cannot only be enhanced but also weakened by the radiation field, while that in the x-y plane is only weakened. In this way, the binding energy of the states with odd z parity, like 2p(z) can be decreased or increased with respect to its static binding energy by the radiation field, while that of the other states can be only decreased. Furthermore, all binding energies become insensitive to the magnetic field if the radiation field is strong. The magnetopolaron effect on these energies is studied within second-order time-dependent perturbation theory. In the nonresonant region, a laser-modulated magnetopolaron correction, including the effect of single-photon processes, is observed. In the resonant region, a laser-modulated magnetopolaron effect, accompanied by the emission and absorption of a single photon, is found. Moreover, the 1s -> 2p(+) transition, accompanied by the emission of a single photon, is tuned by the radiation field into resonance with the longitudinal-optical phonon branch. This is electrically analogous to the magnetopolaron effect, and therefore we name it the dynamical magnetopolaron effect. Finally, by changing the frequency of the radiation field, these interesting effects can be tuned to be far away from the reststrahlen band and, therefore, can be detected experimentally. This in turn provides a direct measure of the electron-phonon interaction.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000457057500001 Publication Date 2019-01-29
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 6 Open Access
Notes ; This work was supported by National Natural Science Foundation of China (Grants No. 11404214, No. 11455015, and No. 61504016) and the China Scholarship Council (CSC), and Science and Technology Research Foundation of Jiangxi Provincial Education Department (Grants No. GJJ161062 and No. GJJ180868). B.V.D. was supported by the Research Foundation – Flanders (FWO-Vl) through a postdoctoral fellowship. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:157555 Serial 5218
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Author Yorulmaz, B.; Ozden, A.; Sar, H.; Ay, F.; Sevik, C.; Perkgoz, N.K.
Title CVD growth of monolayer WS2 through controlled seed formation and vapor density Type A1 Journal article
Year 2019 Publication Materials science in semiconductor processing Abbreviated Journal
Volume 93 Issue Pages 158-163
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Large area, single layer WS2 has a high potential for use in optoelectrical devices with its high photo-luminescence intensity and low response time. In this work, we demonstrate a systematic study of controlled tungsten disulfide (WS2) monolayer growth using chemical vapor deposition (CVD) technique. With a detailed investigation of process parameters such as H-2 gas inclusion into the main carrier gas, growth temperature and duration, we have gained insight into two-dimensional (2D) WS2 synthesis through controlling the seed formations and the radical vapor density associated with WO3. We confirm that H-2 gas, when included to the carrier gas, is directly involved in WO3 reduction due to its reductive reagent nature, which provides a more effective sulfurization and monolayer formation process. Additionally, by changing the CVD growth configuration, hence, increasing the tungsten related vapor density and confining the reactant radicals, we succeed in realizing larger WS(2 )monolayers, which is still a technological challenge in order to utilize these structures for practical applications. Further optimization of the growth procedure is demonstrated by tuning the growth duration to prevent the excess seed formations and additional layers which will possibly limit the device performance of the monolayer flakes or films when applied.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000457727300018 Publication Date 2019-01-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1369-8001 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:193782 Serial 7748
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Author Tiwari, S.; Van de Put, M.L.; Sorée, B.; Vandenberghe, W.G.
Title Carrier transport in two-dimensional topological insulator nanoribbons in the presence of vacancy defects Type A1 Journal article
Year 2019 Publication 2D materials Abbreviated Journal 2D Mater
Volume 6 Issue 2 Pages 025011
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using the non-equilibrium Green's function formalism, we study carrier transport through imperfect two-dimensional (2D) topological insulator (TI) ribbons. In particular, we investigate the effect of vacancy defects on the carrier transport in 2D TI ribbons with hexagonal lattice structure. To account for the random distribution of the vacancy defects, we present a statistical study of varying defect densities by stochastically sampling different defect configurations. We demonstrate that the topological edge states of TI ribbons are fairly robust against a high concentration (up to 2%) of defects. At very high defect densities, we observe an increased inter-edge interaction, mediated by the localisation of the edge states within the bulk region. This effect causes significant back-scattering of the, otherwise protected, edge-states at very high defect concentrations (>2%), resulting in a loss of conduction through the TI ribbon. We discuss how this coherent vacancy scattering can be used to our advantage for the development of TI-based transistors. We find that there is an optimal concentration of vacancies yielding an ON-OFF current ratio of up to two orders of magnitude. Finally, we investigate the importance of spin-orbit coupling on the robustness of the edge states in the TI ribbon and show that increased spin-orbit coupling could further increase the ON-OFF ratio.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000457856400002 Publication Date 2019-01-22
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.937 Times cited 3 Open Access
Notes ; This material is based in part upon work supported by the National Science Foundation under Grant Number 1710066. The project or effort depicted was or is sponsored by the Department of Defense, Defense Threat Reduction Agency. The content of the information does not necessarily reflect the position or the policy of the federal government, and no official endorsement should be inferred. This work was supported by imec's Industrial Affiliation Program. ; Approved Most recent IF: 6.937
Call Number UA @ admin @ c:irua:157464 Serial 5198
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Author Moors, K.; Contino, A.; Van de Put, M.L.; Vandenberghe, W.G.; Fischetti, M., V; Magnus, W.; Sorée, B.
Title Theoretical study of scattering in graphene ribbons in the presence of structural and atomistic edge roughness Type A1 Journal article
Year 2019 Publication Physical review materials Abbreviated Journal
Volume 3 Issue 2 Pages 024001
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate the diffusive electron-transport properties of charge-doped graphene ribbons and nanoribbons with imperfect edges. We consider different regimes of edge scattering, ranging from wide graphene ribbons with (partially) diffusive edge scattering to ribbons with large width variations and nanoribbons with atomistic edge roughness. For the latter, we introduce an approach based on pseudopotentials, allowing for an atomistic treatment of the band structure and the scattering potential, on the self-consistent solution of the Boltzmann transport equation within the relaxation-time approximation and taking into account the edge-roughness properties and statistics. The resulting resistivity depends strongly on the ribbon orientation, with zigzag (armchair) ribbons showing the smallest (largest) resistivity and intermediate ribbon orientations exhibiting intermediate resistivity values. The results also show clear resistivity peaks, corresponding to peaks in the density of states due to the confinement-induced subband quantization, except for armchair-edge ribbons that show a very strong width dependence because of their claromatic behavior. Furthermore, we identify a strong interplay between the relative position of the two valleys of graphene along the transport direction, the correlation profile of the atomistic edge roughness, and the chiral valley modes, leading to a peculiar strongly suppressed resistivity regime, most pronounced for the zigzag orientation.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000458161800001 Publication Date 2019-02-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2475-9953 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 4 Open Access
Notes ; We acknowledge the Research Foundation – Flanders (FWO) for supporting K.M.'s research visit at the University of Texas at Dallas, as well as the support by the National Research Fund Luxembourg (FNR) with ATTRACT Grant No. 7556175. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:157499 Serial 5235
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Author Bercx, M.; Partoens, B.; Lamoen, D.
Title 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 (up) 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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Author Lozano, D.P.; Couet, S.; Petermann, C.; Hamoir, G.; Jochum, J.K.; Picot, T.; Menendez, E.; Houben, K.; Joly, V.; Antohe, V.A.; Hu, M.Y.; Leu, B.M.; Alatas, A.; Said, A.H.; Roelants, S.; Partoens, B.; Milošević, M.V.; Peeters, F.M.; Piraux, L.; Van de Vondel, J.; Vantomme, A.; Temst, K.; Van Bael, M.J.
Title Experimental observation of electron-phonon coupling enhancement in Sn nanowires caused by phonon confinement effects Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 6 Pages 064512
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Reducing the size of a superconductor below its characteristic length scales can either enhance or suppress its critical temperature (T-c). Depending on the bulk value of the electron-phonon coupling strength, electronic and phonon confinement effects will play different roles in the modification of T-c. Experimentally disentangling each contribution has remained a challenge. We have measured both the phonon density of states and T-c of Sn nanowires with diameters of 18, 35, and 100 nm in order to quantify the effects of phonon confinement on superconductivity. We observe a shift of the phonon frequency towards the low-energy region and an increase in the electron-phonon coupling constant that can account for the measured increase in T-c.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000459322400005 Publication Date 2019-02-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 8 Open Access
Notes ; We would like to thanks Jeroen Scheerder and Wout Keijers for their help and assistance during the low-temperature measurements. This work was supported by the Research Foundation Flanders (FWO), the Concerted Research Action (GOA/14/ 007), the Federation Wallonie-Bruxelles (ARC 13/18-052, Supracryst) and the Fonds de la Recherche Scientifique -FNRS under Grant No. T.0006.16. The authors acknowledge Hercules Stichting (Project Nos. AKUL/13/19 and AKUL/13/25). D.P.L. thanks the FWO for financial support. This research used resources of the Advanced Photon Source, a US Department of Energy (DOE) Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:158621 Serial 5212
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Author Kahraman, Z.; Kandemir, A.; Yagmurcukardes, M.; Sahin, H.
Title Single-layer Janus-type platinum dichalcogenides and their heterostructures Type A1 Journal article
Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 123 Issue 7 Pages 4549-4557
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Ultrathin two-dimensional Janus-type platinum dichalcogenide crystals formed by two different atoms at opposite surfaces are investigated by performing state-of-the-art density functional theory calculations. First, it is shown that single-layer PtX2 structures (where X = S, Se, or Te) crystallize into the dynamically stable IT phase and are indirect band gap semiconductors. It is also found that the substitutional chalcogen doping in all PtX2 structures is favorable via replacement of surface atoms with a smaller chalcogen atom, and such a process leads to the formation of Janus-type platinum dichalcogenides (XPtY, where X and Y stand for S, Se, or Te) which are novel single-layer crystals. While all Janus structures are indirect band gap semiconductors as their binary analogues, their Raman spectra show distinctive features that stem from the broken out-of-plane symmetry. In addition, it is revealed that the construction of Janus crystals enhances the piezoelectric constants of PtX2 crystals significantly both in the in plane and in the out-of-plane directions. Moreover, it is shown that vertically stacked van der Waals heterostructures of binary and ternary (Janus) platinum dichalcogenides offer a wide range of electronic features by forming bilayer heterojunctions of type-I, type-II, and type-III, respectively. Our findings reveal that Janus-type ultrathin platinum dichalcogenide crystals are quite promising materials for optoelectronic device applications.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000459836900071 Publication Date 2019-01-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 20 Open Access
Notes ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. and Z.K. acknowledge financial support from the TUBITAK under the project number 117F095. This work is supported by the Flemish Science Foundation (FWO-Vl) by a post-doctoral fellowship (M.Y.). H.S. acknowledges support from Turkiye Bilimler Akademisi-Turkish Academy of Sciences under the GEBIP program. ; Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:158617 Serial 5229
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Author Demiroglu, I.; Peeters, F.M.; Gulseren, O.; Cakir, D.; Sevik, C.
Title Alkali metal intercalation in MXene/graphene heterostructures : a new platform for ion battery applications Type A1 Journal article
Year 2019 Publication The journal of physical chemistry letters Abbreviated Journal J Phys Chem Lett
Volume 10 Issue 4 Pages 727-734
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract The adsorption and diffusion of Na, K, and Ca atoms on MXene/graphene heterostructures of MXene systems Sc2C(OH)(2), Ti2CO2, and V2CO2 are systematically investigated by using first-principles methods. We found that alkali metal intercalation is energetically favorable and thermally stable for Ti2CO2/graphene and V2CO2/graphene heterostructures but not for Sc2C(OH)(2). Diffusion kinetics calculations showed the advantage of MXene/graphene heterostructures over sole MXene systems as the energy barriers are halved for the considered alkali metals. Low energy barriers are found for Na and K ions, which are promising for fast charge/discharge rates. Calculated voltage profiles reveal that estimated high capacities can be fully achieved for Na ion in V2CO2/graphene and Ti2CO2/graphene heterostructures. Our results indicate that Ti2CO2/graphene and V2CO2/graphene electrode materials are very promising for Na ion battery applications. The former could be exploited for low voltage applications while the latter will be more appropriate for higher voltages.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000459948800005 Publication Date 2019-01-30
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1948-7185 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 9.353 Times cited 67 Open Access
Notes ; We acknowledge the support from the TUBITAK (116F080) and the BAGEP Award of the Science Academy. Part of this work was supported by the FLAG -ERA project TRANS-2D-TMD. A part of this work was supported by University of North Dakota Early Career Award (Grant number: 20622-4000-02624). We also acknowledge financial support from ND EPSCoR through NSF grant OIA-1355466. Computational resources were provided by the High Performance and Grid Computing Center (TRGrid e-Infrastructure) of TUBITAK ULAKBIM, the National Center for High Performance Computing (UHeM) of Istanbul Technical University, and Computational Research Center (HPC Linux cluster) at the University of North Dakota. This work was performed, in part, at the Center for Nanoscale Materials, a U.S. Department of Energy Office of Science User Facility, and supported by the U.S. Department of Energy, Office of Science, under contract no. DE-AC02-06CH11357. ; Approved Most recent IF: 9.353
Call Number UA @ admin @ c:irua:158618 Serial 5194
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Author Siriwardane, E.M.D.; Demiroglu, I.; Sevik, C.; Cakir, D.
Title Achieving Fast Kinetics and Enhanced Li Storage Capacity for Ti3C2O2 by Intercalation of Quinone Molecules Type A1 Journal article
Year 2019 Publication ACS applied energy materials Abbreviated Journal
Volume 2 Issue 2 Pages 1251-1258
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Using first-principles calculations, we demonstrated that high lithium storage capacity and fast kinetics are achieved for Ti3C2O2 by preintercalating organic molecules. As a proof-of-concept, two different quinone molecules, namely 1,4-benzoquinone (C6H4O2) and tetrafluoro-1,4-benzoquinone (C6F4O2) were selected as the molecular linkers to demonstrate the feasibility of this interlayer engineering strategy for energy storage. As compared to Ti3C2O2 bilayer without linker molecules, our pillared structures facilitate a much faster ion transport, promising a higher charge/discharge rate for Li. For example, while the diffusion barrier of a single Li ion within pristine Ti3C2O2 bilayer is at least 1.0 eV, it becomes 0.3 eV in pillared structures, which is comparable and even lower than that of commercial materials. At high Li concentrations, the calculated diffusion barriers are as low as 0.4 eV. Out-of-plane migration of Li ions is hindered due to large barrier energy with a value of around 1-1.35 eV. Concerning storage capacity, we can only intercalate one monolayer of Li within pristine Ti3C2O2 bilayer. In contrast, pillared structures offer significantly higher storage capacity. Our calculations showed that at least two layers of Li can be intercalated between Ti3C2O2 layers without forming bulk Li and losing the pillared structure upon Li loading/unloading. A small change in the in-plane lattice parameters (<0.5%) and volume (<1.0%) and ab initio molecular dynamics simulations prove the stability of the pillared structures against Li intercalation and thermal effects. Intercalated molecules avoid the large contraction/expansion of the whole structure, which is one of the key problems in electrochemical energy storage. Pillared structures allow us to realize electrodes with high capacity and fast kinetics. Our results open new research paths for improving the performance of not only MXenes but also other layered materials for supercapacitor and battery applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000459948900037 Publication Date 2019-01-04
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2574-0962 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited Open Access
Notes Approved no
Call Number UA @ admin @ c:irua:193759 Serial 7414
Permanent link to this record
 
 
Author Milovanović, S.P.; Covaci, L.; Peeters, F.M.
Title Strain fields in graphene induced by nanopillar mesh Type A1 Journal article
Year 2019 Publication Journal of applied physics Abbreviated Journal J Appl Phys
Volume 125 Issue 8 Pages 082534
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The mechanical and electronic properties of a graphene membrane placed on top of a triangular superlattice of nanopillars are investigated. We use molecular dynamics simulations to access the deformation fields and the tight-binding approaches to calculate the electronic properties. Ripples form in the graphene layer that span across the unit cell, connecting neighboring pillars, in agreement with recent experiments. We find that the resulting pseudo-magnetic field (PMF) varies strongly across the unit cell. We investigate the dependence of PMF on unit cell boundary conditions, height of the pillars, and the strength of the van der Waals interaction between graphene and the substrate. We find direct correspondence with typical experiments on pillars, showing intrinsic “slack” in the graphene membrane. PMF values are confirmed by the local density of states calculations performed at different positions of the unit cell showing pseudo-Landau levels with varying spacings. Our findings regarding the relaxed membrane configuration and the induced strains are transferable to other flexible 2D membranes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000460033800038 Publication Date 2019-01-16
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8979; 1089-7550 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.068 Times cited 5 Open Access
Notes ; S.P.M. is supported by the Flemish Science Foundation (FWO). ; Approved Most recent IF: 2.068
Call Number UA @ admin @ c:irua:158605 Serial 5231
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Author Menezes, R.M.; Mulkers, J.; de Souza Silva, C.C.; Milošević, M.V.
Title Deflection of ferromagnetic and antiferromagnetic skyrmions at heterochiral interfaces Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 10 Pages 104409
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Devising magnetic nanostructures with spatially heterogeneous Dzyaloshinskii-Moriya interaction (DMI) is a promising pathway toward advanced confinement and control of magnetic skyrmions in potential devices. Here we discuss theoretically how a skyrmion interacts with a heterochiral interface using micromagnetic simulations and analytic arguments. We show that a heterochiral interface deflects the trajectory of ferromagnetic (FM) skyrmions, and that the extent of such deflection is tuned by the applied spin-polarized current and the difference in DMI across the interface. Further, we show that this deflection is characteristic of the FM skyrmion, and it is completely absent in the antiferromagnetic (AFM) case. In turn, we reveal that the AFM skyrmion achieves much higher velocities than its FM counterpart, yet experiences far stronger confinement in nanoengineered heterochiral tracks, which reinforces AFM skyrmions as a favorable choice for skyrmion-based devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000460720600005 Publication Date 2019-03-07
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 19 Open Access
Notes ; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen) and Brazilian Agencies FACEPE under Grant No. APQ-0198-1.05/14, CAPES and CNPq. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:158557 Serial 5203
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Author Wang, W.; Li, L.; Kong, X.; Van Duppen, B.; Peeters, F.M.
Title T4,4,4-graphyne : a 2D carbon allotrope with an intrinsic direct bandgap Type A1 Journal article
Year 2019 Publication Solid state communications Abbreviated Journal Solid State Commun
Volume 293 Issue 293 Pages 23-27
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A novel two-dimensional (2D) structurally stable carbon allotrope is proposed using first-principles calculations, which is a promising material for water purification and for electronic devices due to its unique porous structure and electronic properties. Rectangular and hexagonal rings are connected with acetylenic linkages, forming a nanoporous structure with a pore size of 6.41 angstrom, which is known as T-4,T-4,T-4-graphyne. This 2D sheet exhibits a direct bandgap of 0.63 eV at the M point, which originates from the p(z)( )atomic orbitals of carbon atoms as confirmed by a tight-binding model. Importantly, T-4,T-4,T-4-graphyne is found to be energetically more preferable than the experimentally realized beta-graphdiyne, it is dynamically stable and can withstand temperatures up to 1500 K.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000460909600005 Publication Date 2019-02-10
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0038-1098 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.554 Times cited 10 Open Access
Notes ; This work was supported by National Natural Science Foundation of China (Grant Nos. 11404214 and 11455015), the China Scholarship Council (CSC), the Science and Technology Research Foundation of Jiangxi Provincial Education Department (Grant Nos. GJJ180868 and GJJ161062) the Fonds Wetenschappelijk Onderzoek (FWO-V1), and the FLAG-ERA project TRANS2DTMD. BVD was supported by the Research Foundation – Flanders (FWO-V1) through a postdoctoral fellowship. 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. ; Approved Most recent IF: 1.554
Call Number UA @ admin @ c:irua:158503 Serial 5234
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Author Marikutsa, A.; Rumyantseva, M.; Gaskov, A.; Batuk, M.; Hadermann, J.; Sarmadian, N.; Saniz, R.; Partoens, B.; Lamoen, D.
Title Effect of zinc oxide modification by indium oxide on microstructure, adsorbed surface species, and sensitivity to CO Type A1 Journal article
Year 2019 Publication Frontiers in materials Abbreviated Journal
Volume 6 Issue 6 Pages
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Additives in semiconductor metal oxides are commonly used to improve sensing behavior of gas sensors. Due to complicated effects of additives on the materials microstructure, adsorption sites and reactivity to target gases the sensing mechanism with modified metal oxides is a matter of thorough research. Herein, we establish the promoting effect of nanocrystalline zinc oxide modification by 1-7 at.% of indium on the sensitivity to CO gas due to improved nanostructure dispersion and concentration of active sites. The sensing materials were synthesized via an aqueous coprecipitation route. Materials composition, particle size and BET area were evaluated using X-ray diffraction, nitrogen adsorption isotherms, high-resolution electron microscopy techniques and EDX-mapping. Surface species of chemisorbed oxygen, OH-groups, and acid sites were characterized by probe molecule techniques and infrared spectroscopy. It was found that particle size of zinc oxide decreased and the BET area increased with the amount of indium oxide. The additive was observed as amorphous indium oxide segregated on agglomerated ZnO nanocrystals. The measured concentration of surface species was higher on In2O3-modified zinc oxide. With the increase of indium oxide content, the sensor response of ZnO/In2O3 to CO was improved. Using in situ infrared spectroscopy, it was shown that oxidation of CO molecules was enhanced on the modified zinc oxide surface. The effect of modifier was attributed to promotion of surface OH-groups and enhancement of CO oxidation on the segregated indium ions, as suggested by DFT in previous work.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000461540600001 Publication Date 2019-03-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2296-8016 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 11 Open Access OpenAccess
Notes ; Research was supported by the grant from Russian Science Foundation (project No. 18-73-00071). ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:158540 Serial 5205
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Author Aslani, Z.; Sisakht, E.T.; Fazileh, F.; Ghorbanfekr-Kalashami, H.; Peeters, F.M.
Title Conductance fluctuations of monolayer GeSnH2$ in the topological phase using a low-energy effective tight-binding Hamiltonian Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 11 Pages 115421
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract An effective tight-binding (TB) Hamiltonian for monolayer GeSnH2 is constructed which has an inversion-asymmetric honeycomb structure. The low-energy band structure of our TB model agrees very well with previous ab initio calculations even under biaxial tensile strain. Our model predicts a phase transition at 7.5% biaxial tensile strain in agreement with DFT calculations. Upon 8.5% strain the system exhibits a band gap of 134 meV, suitable for room temperature applications. It is shown that an external applied magnetic field produces a special phase which is a combination of the quantum Hall (QH) and quantum spin Hall (QSH) phases; and at a critical magnetic field strength the QSH phase completely disappears. The topological nature of the phase transition is confirmed from: (1) the calculation of the Z(2) topological invariant, and (2) quantum transport properties of disordered GeSnH2 nanoribbons which allows us to determine the universality class of the conductance fluctuations. The application of an external applied magnetic field reduces the conductance fluctuations by a factor of root 2.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000461958900006 Publication Date 2019-03-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 2 Open Access
Notes ; This work was supported by the FLAG-ERA project TRANS-2D-TMD. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:158538 Serial 5199
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Author Neek-Amal, M.; Rashidi, R.; Nair, R.R.; Neilson, D.; Peeters, F.M.
Title Electric-field-induced emergent electrical connectivity in graphene oxide Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 11 Pages 115425
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Understanding the appearance of local electrical connectivity in liquid filled layered graphene oxide subjected to an external electric field is important to design electrically controlled smart permeable devices and also to gain insight into the physics behind electrical effects on confined water permeation. Motivated by recent experiments [K. G. Zhou et al. Nature (London) 559, 236 (2018)], we introduce a new model with random percolating paths for electrical connectivity in micron thick water filled layered graphene oxide, which mimics parallel resistors connected across the top and bottom electrodes. We find that a strong nonuniform radial electric field of the order similar to 10-50 mV/nm can be induced between layers depending on the current flow through the formed conducting paths. The maxima of the induced fields are not necessarily close to the electrodes and may be localized in the middle region of the layered material. The emergence of electrical connectivity and the associated electrical effects have a strong influence on the surrounding fluid in terms of ionization and wetting which subsequently determines the permeation properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000461960100001 Publication Date 2019-03-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 3 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:158534 Serial 5206
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Author Van der Donck, M.; Peeters, F.M.
Title Spectrum of exciton states in monolayer transition metal dichalcogenides : angular momentum and Landau levels Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 11 Pages 115439
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract A four-band exciton Hamiltonian is constructed starting from the single-particle Dirac Hamiltonian for charge carriers in monolayer transition metal dichalcogenides (TMDs). The angular part of the exciton wave function can be separated from the radial part, in the case of zero center of mass momentum excitons, by exploiting the eigenstates of the total exciton angular momentum operator with which the Hamiltonian commutes. We explain why this approach fails for excitons with finite center of mass momentum or in the presence of a perpendicular magnetic field and present an approximation to resolve this issue. We calculate the (binding) energy and average interparticle distance of different excited exciton states in different TMDs and compare these with results available in the literature. Remarkably, we find that the intervalley exciton ground state in the -/+ K valley has angular momentum j = +/- 1, which is due to the pseudospin of the separate particles. The exciton mass and the exciton Landau levels are calculated and we find that the degeneracy of exciton states with opposite relative angular momentum is altered by a magnetic field.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000462896400004 Publication Date 2019-03-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 9 Open Access
Notes ; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the FLAG-ERA project TRANS-2D-TMD. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:159406 Serial 5230
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Author Van Pottelberge, R.; Peeters, F.M.
Title Tunable circular dipolelike system in graphene : mixed electron-hole states Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 12 Pages 125426
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Coupled electron-hole states are realized in a system consisting of a combination of an electrostatic potential barrier and ring-shaped potential well, which resembles a circular dipole. A perpendicular magnetic field induces confined states inside the Landau gaps which are mainly located at the barrier or ring. Hybridizations between the barrier and ring states are seen as anticrossings in the energy spectrum. As a consequence, the energy levels show an oscillating dependence on the electrostatic potential strength in combination with an oscillating migration of the wave functions between the barrier and ring. At the anticrossing points the quantum state consists of a mixture of electron and hole. The present system mimics closely the behavior of a relativistic dipole on gapped graphene.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000462900200005 Publication Date 2019-03-27
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.836 Times cited 3 Open Access
Notes ; We thank M. Van der Donck for fruitful discussions. This work was supported by the Research Foundation of Flanders (FWO-V1) through an aspirant research grant for RVP. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:159409 Serial 5237
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Author Kong, X.; Li, L.; Peeters, F.M.
Title Graphene-based heterostructures with moire superlattice that preserve the Dirac cone: a first-principles study Type A1 Journal article
Year 2019 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 31 Issue 25 Pages 255302
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In van der Waals heterostructures consisting of graphene and a substrate, lattice mismatch often leads to a moire pattern with a huge supercell, preventing its treatment within first- principles calculations. Previous theoretical works considered mostly simple stacking models such as AB, AA with straining the lattice of graphene to match that of the substrate. Here, we propose a moire superlattice build from graphene and porous graphene or graphyne like monolayers, having a lower interlayer binding energy, needing little strain in order to match the lattices. In contrast to the results from the simple stacking models, the present ab initio calculations for the moire superlattices show different properties in lattice structure, energy, and band structures. For example, the Dirac cone at the K point is preserved and a linear energy dispersion near the Fermi level is obtained.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000464184300001 Publication Date 2019-03-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 4 Open Access
Notes ; This work is supported by the Collaborative Innovation Center of Quantum Matter, the Fonds voor Wetenschappelijk Onderzoek (FWO-Vl) and the FLAG-ERA project TRANS-2D-TMD. 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: 2.649
Call Number UA @ admin @ c:irua:159314 Serial 5215
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Author Rezvani, S.J.; Perali, A.; Fretto, M.; De Leo, N.; Flammia, L.; Milošević, M.; Nannarone, S.; Pinto, N.
Title Substrate-induced proximity effect in superconducting niobium nanofilms Type A1 Journal article
Year 2018 Publication Condensed Matter Abbreviated Journal
Volume 4 Issue 1 Pages 4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Structural and superconducting properties of high-quality niobium nanofilms with different thicknesses are investigated on silicon oxide (SiO2) and sapphire substrates. The role played by the different substrates and the superconducting properties of the Nb films are discussed based on the defectivity of the films and on the presence of an interfacial oxide layer between the Nb film and the substrate. The X-ray absorption spectroscopy is employed to uncover the structure of the interfacial layer. We show that this interfacial layer leads to a strong proximity effect, especially in films deposited on a SiO2 substrate, altering the superconducting properties of the Nb films. Our results establish that the critical temperature is determined by an interplay between quantum-size effects, due to the reduction of the Nb film thicknesses, and proximity effects. The detailed investigation here provides reference characterizations and has direct and important implications for the fabrication of superconducting devices based on Nb nanofilms.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000464289300001 Publication Date 2018-12-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2410-3896 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 3 Open Access
Notes ; This project was financially supported by University of Camerino, FAR project CESEMN. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:159463 Serial 5233
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Author Scuracchio, P.; Michel, K.H.; Peeters, F.M.
Title 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 (up) 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 Torre, I.; de Castro, L.V.; Van Duppen, B.; Barcons Ruiz, D.; Peeters, F.M.; Koppens, F.H.L.; Polini, M.
Title Acoustic plasmons at the crossover between the collisionless and hydrodynamic regimes in two-dimensional electron liquids Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 14 Pages 144307
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Hydrodynamic flow in two-dimensional electron systems has so far been probed only by dc transport and scanning gate microscopy measurements. In this work we discuss theoretically signatures of the hydrodynamic regime in near-field optical microscopy. We analyze the dispersion of acoustic plasmon modes in two-dimensional electron liquids using a nonlocal conductivity that takes into account the effects of (momentumconserving) electron-electron collisions, (momentum-relaxing) electron-phonon and electron-impurity collisions, and many-body interactions beyond the celebrated random phase approximation. We derive the dispersion and, most importantly, the damping of acoustic plasmon modes and their coupling to a near-field probe, identifying key experimental signatures of the crossover between collisionless and hydrodynamic regimes.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000465160000003 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 10 Open Access
Notes ; This work has been sponsored by the European Union's Horizon 2020 research and innovation programme under Grant Agreement No. 785219 “Graphene Core2” and via the European Research Council (ERC) Grant Agreement No. 786285. B.V.D. is supported by a post-doctoral fellowship of the Flemish Science Foundation (FWO-Vl). F.H.L.K. acknowledges financial support from the Spanish Ministry of Economy and Competitiveness, through the “ Severo Ochoa” Programme for Centres of Excellence in R&D (SEV-2015-0522), support by Fundacio Cellex Barcelona, Generalitat de Catalunya through the CERCA program, and the Mineco grant Plan Nacional (FIS2016-81044-P) and the Agency for Management of University and Research Grants (AGAUR) 2017 SGR 1656. F.M.P. and L.V.d.C. were supported by the Methusalem Program of the Flemish Government. We thank Niels Hesp and Hanan Hertzig Sheinfux for useful discussions. ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:159333 Serial 5193
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Author Conti, S.; Perali, A.; Peeters, F.M.; Neilson, D.
Title 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 (up) 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 Gonzalez-Garcia, A.; Lopez-Perez, W.; Gonzalez-Hernandez, R.; Rodriguez, J.A.; Milošević, M.V.; Peeters, F.M.
Title Tunable 2D-gallium arsenide and graphene bandgaps in a graphene/GaAs heterostructure : an ab initio study Type A1 Journal article
Year 2019 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat
Volume 31 Issue 26 Pages 265502
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The bandgap behavior of 2D-GaAs and graphene have been investigated with van der Waals heterostructured into a yet unexplored graphene/GaAs bilayer, under both uniaxial stress along c axis and different planar strain distributions. The 2D-GaAs bandgap nature changes from Gamma-K indirect in isolated monolayer to Gamma-Gamma direct in graphene/GaAs bilayer. In the latter, graphene exhibits a bandgap of 5 meV. The uniaxial stress strongly affects the graphene electronic bandgap, while symmetric in-plane strain does not open the bandgap in graphene. Nevertheless, it induces remarkable changes on the GaAs bandgap-width around the Fermi level. However, when applying asymmetric in-plane strain to graphene/GaAs, the graphene sublattice symmetry is broken, and the graphene bandgap is open at the Fermi level to a maximum width of 814 meV. This value is much higher than that reported for just graphene under asymmetric strain. The Gamma-Gamma direct bandgap of GaAs remains unchanged in graphene/ GaAs under different types of applied strain. The analyses of phonon dispersion and the elastic constants yield the dynamical and mechanical stability of the graphene/GaAs system, respectively. The calculated mechanical properties for bilayer heterostructure are better than those of their constituent monolayers. This finding, together with the tunable graphene bandgap not only by the strength but also by the direction of the strain, enhance the potential for strain engineering of ultrathin group-III-V electronic devices hybridized by graphene.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000465887100001 Publication Date 2019-03-06
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.649 Times cited 6 Open Access
Notes ; This work has been carried out with the financial support of Universidad del Norte and Colciencias (Administrative Department of Science, Technology and Research of Colombia) under Convocatoria 712-Convocatoria para proyectos de investigacion en Ciencias Basicas, ano 2015, Cod: 121571250192, Contrato 110-216; and the partial support of DGAPA-UNAM project IN114817-3. The authors gratefully acknowledge the support from the High Performance Computing core facility CalcUA and the TOPBOF project at the University of Antwerp, Belgium; DGTIC-UNAM under project LANCAD-UNAM-DGTIC-150, and the computing time granted on the supercomputer Mogon at Johannes Gutenberg University Mainz (hpc.uni-mainz.de). ; Approved Most recent IF: 2.649
Call Number UA @ admin @ c:irua:160216 Serial 5236
Permanent link to this record
 
 
Author Bercx, M.; Slap, L.; Partoens, B.; Lamoen, D.
Title First-Principles Investigation of the Stability of the Oxygen Framework of Li-Rich Battery Cathodes Type A1 Journal article
Year 2019 Publication MRS advances Abbreviated Journal MRS Adv.
Volume 4 Issue 14 Pages 813-820
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract Lithium-rich layered oxides such as Li<sub>2</sub>MnO<sub>3</sub>have shown great potential as cathodes in Li-ion batteries, mainly because of their large capacities. However, these materials still suffer from structural degradation as the battery is cycled, reducing the average voltage and capacity of the cell. The voltage fade is believed to be related to the migration of transition metals into the lithium layer, linked to the formation of O-O dimers with a short bond length, which in turn is driven by the presence of oxygen holes due to the participation of oxygen in the redox process. We investigate the formation of O-O dimers for partially charged O1-Li<sub>2</sub>MnO<sub>3</sub>using a first-principles density functional theory approach by calculating the reaction energy and kinetic barriers for dimer formation. Next, we perform similar calculations for partially charged O1-Li<sub>2</sub>IrO<sub>3</sub>, a Li-rich material for which the voltage fade was not observed during cycling. When we compare the stability of the oxygen framework, we conclude that the formation of O-O dimers is both thermodynamically and kinetically viable for O1-Li<sub>0.5</sub>MnO<sub>3</sub>. For O1-Li<sub>0.5</sub>IrO<sub>3</sub>, we observe that the oxygen lattice is much more stable, either returning to its original state when perturbed, or resulting in a structure with an O-O dimer that is much higher in energy. This can be explained by the mixed redox process for Li<sub>2</sub>IrO<sub>3</sub>, which is also shown from the calculated magnetic moments. The lack of O-O dimer formation in O1-Li<sub>0.5</sub>IrO<sub>3</sub>provides valuable insight as to why Li<sub>2</sub>IrO<sub>3</sub>does not demonstrate a voltage fade as the battery is cycled, which can be used to design Li-rich battery cathodes with an improved cycling performance.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000466846700004 Publication Date 2019-02-21
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2059-8521 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 3 Open Access Not_Open_Access: Available from 22.02.2020
Notes We acknowledge the financial support of FWO-Vlaanderen through project G040116N. 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 FWO-Vlaanderen and the Flemish Government-department EWI. Approved Most recent IF: NA
Call Number EMAT @ emat @UA @ admin @ c:irua:160121 Serial 5179
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Author Yagmurcukardes, M.; Ozen, S.; Iyikanat, F.; Peeters, F.M.; Sahin, H.
Title Raman fingerprint of stacking order in HfS2-Ca(OH)(2) heterobilayer Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 20 Pages 205405
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using density functional theory-based first-principles calculations, we investigate the stacking order dependence of the electronic and vibrational properties of HfS2-Ca(OH)(2) heterobilayer structures. It is shown that while the different stacking types exhibit similar electronic and optical properties, they are distinguishable from each other in terms of their vibrational properties. Our findings on the vibrational properties are the following: (i) from the interlayer shear (SM) and layer breathing (LBM) modes we are able to deduce the AB' stacking order, (ii) in addition, the AB' stacking type can also be identified via the phonon softening of E-g(I) and A(g)(III) modes which harden in the other two stacking types, and (iii) importantly, the ultrahigh frequency regime possesses distinctive properties from which we can distinguish between all stacking types. Moreover, the differences in optical and vibrational properties of various stacking types are driven by two physical effects, induced biaxial strain on the layers and the layer-layer interaction. Our results reveal that with both the phonon frequencies and corresponding activities, the Raman spectrum possesses distinctive properties for monitoring the stacking type in novel vertical heterostructures constructed by alkaline-earth-metal hydroxides.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000467387800010 Publication Date 2019-05-06
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 23 Open Access
Notes ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). H.S. acknowledges financial support from the Scientific and Technological Research Council of Turkey (TUBITAK) under the Project No. 117F095. H.S. acknowledges support from Turkish Academy of Sciences under the GEBIP program. 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:160334 Serial 5226
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Author Bafekry, A.; Shayesteh, S.F.; Peeters, F.M.
Title C3N Monolayer: Exploring the Emerging of Novel Electronic and Magnetic Properties with Adatom Adsorption, Functionalizations, Electric Field, Charging, and Strain Type A1 Journal article
Year 2019 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
Volume 123 Issue 19 Pages 12485-12499
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Two-dimensional polyaniline with structural unit C3N is an indirect semiconductor with 0.4 eV band gap, which has attracted a lot of interest because of its unusual electronic, optoelectronic, thermal, and mechanical properties useful for various applications. Adsorption of adatoms is an effective method to improve and tune the properties of C3N. Using first-principles calculations, we investigated the adsorption of adatoms, including H, O, S, F, Cl, B, C, Si, N, P, Al, Li, Na, K, Be, Mg, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Zn, on C3N. Depending on the adatom size and the number of valence electrons, they may induce metallic, half-metallic, semiconducting, and ferromagnetic-metallic behavior. In addition, we investigate the effects of an electrical field, charging, and strain on C3N and found how the electronic and magnetic properties are modified. Semi- and full hydrogenation are studied. From the mechanical and thermal stability of C3N monolayer, we found it to be a hard material that can withstand large strain. From our calculations, we gained novel insights into the properties of C3N demonstrating its unique electronic and magnetic properties that can be useful for semiconducting, nanosensor, and catalytic applications.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000468368800053 Publication Date 2019-04-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1932-7447; 1932-7455 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.536 Times cited 67 Open Access
Notes ; This work was supported by the Flemish Science Foundation (FW0-V1). The authors thank Keyvan Nazifi from the Cluster Center of Faculty of Science, Guilan University, for his help. They acknowledge OpenMX team for OpenMX code. ; Approved Most recent IF: 4.536
Call Number UA @ admin @ c:irua:160323 Serial 5196
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Author Yuan, H.F.; Xu, W.; Zhao, X.N.; Song, D.; Zhang, G.R.; Xiao, Y.M.; Ding, L.; Peeters, F.M.
Title Quantum and transport mobilities of a Na3Bi-based three-dimensional Dirac system Type A1 Journal article
Year 2019 Publication Physical review B Abbreviated Journal Phys Rev B
Volume 99 Issue 23 Pages 235303
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The electronic and transport properties of a three-dimensional (3D) Dirac system are investigated theoretically, which is motivated by recent experimental measurements on quantum and transport mobilities in the 3D Dirac semimetal Na3Bi by J. Xiong et al. [Science 350, 413 (2015); Europhys. Lett. 114, 27002 (2016)]. The electron Hamiltonian is taken from a simplified k center dot p approach. From the obtained electronic band structure and the Fermi energy, we explain why the anomalous effect induced by the chiral anomaly and the Berry curvature in the energy band can be observed experimentally in magnetotransport coefficients in both low-and high-density samples. Moreover, the quantum and transport mobilities are calculated on the basis of the momentum-balance equation derived from a semiclassical Boltzmann equation with the electron-impurity interaction. The quantum and transport mobilities obtained from this study agree both qualitatively and quantitatively with those measured experimentally. We also examine the electron mobilities along different crystal directions in Na3Bi and find them largely anisotropic. The theoretical findings from this work can be helpful in gaining an in-depth understanding of the experimental results and of the basic electronic and transport properties of newly developed 3D Dirac systems.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000471983500006 Publication Date 2019-06-17
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; WoS citing articles
Impact Factor 3.836 Times cited 1 Open Access
Notes ; ; Approved Most recent IF: 3.836
Call Number UA @ admin @ c:irua:161329 Serial 5425
Permanent link to this record
 
 
Author Saniz, R.; Sarmadian, N.; Partoens, B.; Batuk, M.; Hadermann, J.; Marikutsa, A.; Rumyantseva, M.; Gaskov, A.; Lamoen, D.
Title First-principles study of CO and OH adsorption on in-doped ZnO surfaces Type A1 Journal article
Year 2019 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids
Volume 132 Issue Pages 172-181
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We present a first-principles computational study of CO and OH adsorption on non-polar ZnO (10¯10) surfaces doped with indium. The calculations were performed using a model ZnO slab. The position of the In dopants was varied from deep bulk-like layers to

the surface layers. It was established that the preferential location of the In atoms is at the surface by examining the dependence of

the defect formation energy as well as the surface energy on In location. The adsorption sites on the surface of ZnO and the energy

of adsorption of CO molecules and OH-species were determined in connection to In doping. It was found that OH has higher

bonding energy to the surface than CO. The presence of In atoms at the surface of ZnO is favorable for CO adsorption, resulting

in an elongation of the C-O bond and in charge transfer to the surface. The effect of CO and OH adsorption on the electronic

and conduction properties of surfaces was assessed. We conclude that In-doped ZnO surfaces should present a higher electronic

response upon adsorption of CO.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000472124700023 Publication Date 2019-04-25
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3697 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.059 Times cited 7 Open Access Not_Open_Access: Available from 26.04.2021
Notes FWO-Vlaanderen, G0D6515N ; ERA.Net RUS Plus, 096 ; VSC; HPC infrastructure of the University of Antwerp; FWO-Vlaanderen; Flemish Government-department EWI; Approved Most recent IF: 2.059
Call Number EMAT @ emat @UA @ admin @ c:irua:159656 Serial 5170
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Author Li, L.L.; Peeters, F.M.
Title Strain engineered linear dichroism and Faraday rotation in few-layer phosphorene Type A1 Journal article
Year 2019 Publication Applied physics letters Abbreviated Journal Appl Phys Lett
Volume 114 Issue 24 Pages 243102
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate theoretically the linear dichroism and the Faraday rotation of strained few-layer phosphorene, where strain is applied uniaxially along the armchair or zigzag direction of the phosphorene lattice. We calculate the optical conductivity tensor of uniaxially strained few-layer phosphorene by means of the Kubo formula within the tight-binding approach. We show that the linear dichroism and the Faraday rotation of few-layer phosphorene can be significantly modulated by the applied strain. The modulation depends strongly on both the magnitude and direction of strain and becomes more pronounced with increasing number of phosphorene layers. Our results are relevant for mechano-optoelectronic applications based on optical absorption and Hall effects in strained few-layer phosphorene.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000472599100029 Publication Date 2019-06-17
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0003-6951; 1077-3118 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.411 Times cited 11 Open Access
Notes ; This work was financially supported by the Flemish Science Foundation (FWO-Vl) and by the FLAG-ERA Project TRANS-2D-TMD. ; Approved Most recent IF: 3.411
Call Number UA @ admin @ c:irua:161327 Serial 5428
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Author De Beule, C.; Saniz, R.; Partoens, B.
Title Crystalline topological states at a topological insulator junction Type A1 Journal article
Year 2019 Publication The journal of physics and chemistry of solids Abbreviated Journal J Phys Chem Solids
Volume 128 Issue 128 Pages 144-151
Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract We consider an interface between two strong time-reversal invariant topological insulators having surface states with opposite spin chirality, or equivalently, opposite mirror Chern number. We show that such an interface supports gapless modes that are protected by mirror symmetry. The interface states are investigated with a continuum model for the Bi2Se3 class of topological insulators that takes into account terms up to third order in the crystal momentum, which ensures that the model has the correct symmetry. The model parameters are obtained from ab initio calculations. Finally, we consider the effect of rotational mismatch at the interface, which breaks the mirror symmetry and opens a gap in the interface spectrum.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos (up) 000472693100013 Publication Date 2018-01-31
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3697 ISBN Additional Links UA library record; WoS full record
Impact Factor 2.059 Times cited Open Access
Notes ; ; Approved Most recent IF: 2.059
Call Number UA @ admin @ c:irua:161391 Serial 5385
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