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Author Hai, G.-Q.; Candido, L.; Brito, B.G.A.; Peeters, F.M. url  doi
openurl 
  Title Electron pairing: from metastable electron pair to bipolaron Type A1 Journal article
  Year 2018 Publication Journal of physics communications Abbreviated Journal  
  Volume 2 Issue 3 Pages Unsp 035017  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Starting from the shell structure in atoms and the significant correlation within electron pairs, we distinguish the exchange-correlation effects between two electrons of opposite spins occupying the same orbital from the average correlation among many electrons in a crystal. In the periodic potential of the crystal with lattice constant larger than the effective Bohr radius of the valence electrons, these correlated electron pairs can form a metastable energy band above the corresponding single-electron band separated by an energy gap. In order to determine if these metastable electron pairs can be stabilized, we calculate the many-electron exchange-correlation renormalization and the polaron correction to the two-band system with single electrons and electron pairs. We find that the electron-phonon interaction is essential to counterbalance the Coulomb repulsion and to stabilize the electron pairs. The interplay of the electron-electron and electron-phonon interactions, manifested in the exchange-correlation energies, polaron effects, and screening, is responsible for the formation of electron pairs (bipolarons) that are located on the Fermi surface of the single-electron band.  
  Address  
  Corporate Author Thesis  
  Publisher IOP Publishing Place of Publication Bristol Editor  
  Language Wos 000434996900022 Publication Date (up) 2018-02-13  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2399-6528 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 9 Open Access  
  Notes ; This work was supported by the Brazilian agencies FAPESP and CNPq. GQH would like to thank Prof. Bangfen Zhu for his invaluable support and expert advice. ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:152079UA @ admin @ c:irua:152079 Serial 5022  
Permanent link to this record
 

 
Author Van der Donck, M.; Zarenia, M.; Peeters, F.M. url  doi
openurl 
  Title Strong valley Zeeman effect of dark excitons in monolayer transition metal dichalcogenides in a tilted magnetic field Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 8 Pages 081109  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The dependence of the excitonic photoluminescence (PL) spectrum of monolayer transition metal dichalcogenides (TMDs) on the tilt angle of an applied magnetic field is studied. Starting from a four-band Hamiltonian we construct a theory which quantitatively reproduces the available experimental PL spectra for perpendicular and in-plane magnetic fields. In the presence of a tilted magnetic field, we demonstrate that the dark exciton PL peaks brighten due to the in-plane component of the magnetic field and split for light with different circular polarizations as a consequence of the perpendicular component of the magnetic field. This splitting is more than twice as large as the splitting of the bright exciton peaks in tungsten-based TMDs. We propose an experimental setup that will allow for accessing the predicted splitting of the dark exciton peaks in the PL spectrum.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000425603600001 Publication Date (up) 2018-02-21  
  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 21 Open Access  
  Notes ; This Rapid Communication was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for MVDD and by the Methusalem Foundation of the Flemish Government. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:149913UA @ admin @ c:irua:149913 Serial 4948  
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Author Pereira, J.R.V.; Tunes, T.M.; De Arruda, A.S.; Godoy, M. pdf  url
doi  openurl
  Title Thermal properties of the mixed spin-1 and spin-3/2 Ising ferrimagnetic system with two different random single-ion anisotropies Type A1 Journal article
  Year 2018 Publication Physica: A : theoretical and statistical physics Abbreviated Journal Physica A  
  Volume 500 Issue 500 Pages 265-272  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract In this work, we have performed Monte Carlo simulations to study a mixed spin-1 and spin-3/2 Ising ferrimagnetic system on a square lattice with two different random single-ion anisotropies. This lattice is divided in two interpenetrating sublattices with spins S-A = 1 in the sublattice A and S-B = 3/2 in the sublattice B. The exchange interaction between the spins on the sublattices is antiferromagnetic (J < 0). We used two random single-ion anisotropies, D-i(A) and D-j(B), on the sublattices A and B, respectively. We have determined the phase diagram of the model in the critical temperature T-c versus strength of the random single-ion anisotropy D plane and we shown that it exhibits only second-order phase transition lines. We also shown that this system displays compensation temperatures for some cases of the random single-ion distribution. (C) 2018 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000430027400025 Publication Date (up) 2018-02-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0378-4371 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.243 Times cited 3 Open Access  
  Notes ; The authors acknowledge financial support by the Brazilian agencies CNPq, Brazil, CAPES, Brazil (Grant No. 88881.120851/2016-01) and FAPEMAT, Brazil. ; Approved Most recent IF: 2.243  
  Call Number UA @ lucian @ c:irua:150706UA @ admin @ c:irua:150706 Serial 4985  
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Author Chen, Q.; Li, L.L.; Peeters, F.M. url  doi
openurl 
  Title Magnetic field dependence of electronic properties of MoS2 quantum dots with different edges Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 8 Pages 085437  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Using the tight-binding approach, we investigate the energy spectrum of square, triangular, and hexagonal MoS2 quantum dots (QDs) in the presence of a perpendicular magnetic field. Novel edge states emerge in MoS2 QDs, which are distributed over the whole edge which we call ring states. The ring states are robust in the presence of spin-orbit coupling (SOC). The corresponding energy levels of the ring states oscillate as a function of the perpendicular magnetic field which are related to Aharonov-Bohm oscillations. Oscillations in the magnetic field dependence of the energy levels and the peaks in the magneto-optical spectrum emerge (disappear) as the ring states are formed (collapsed). The period and the amplitude of the oscillation decrease with the size of the MoS2 QDs.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000426042800009 Publication Date (up) 2018-02-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 18 Open Access  
  Notes ; Q. Chen acknowledges financial support from the (China Scholarship Council (CSC)). This work was also supported by Hunan Provincial Natural Science Foundation of China (Grant No. 2015JJ2040) and by the Scientific Research Fund of Hunan Provincial Education Department (Grant No. 15A042). Additional support from the FLAG-ERA TRANS-2D-TMD is acknowledged. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:149905UA @ admin @ c:irua:149905 Serial 4941  
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Author Wang, W.; Van Duppen, B.; Van der Donck, M.; Peeters, F.M. url  doi
openurl 
  Title Magnetopolaron effect on shallow-impurity states in the presence of magnetic and intense terahertz laser fields in the Faraday configuration Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 6 Pages 064108  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The magnetopolaron effect on shallow-impurity states in semiconductors is investigated when subjected simultaneously to a magnetic field and an intense terahertz laser field within the Faraday configuration. We use a time-dependent nonperturbative theory to describe electron interactions. The externally applied fields are exactly included via a laser-dressed interaction potential. Through a variational approach we evaluate the binding energy of the shallow-impurity states. We find that the interaction strength of the laser-dressed Coulomb potential can not only be enhanced but also weakened by varying the two external fields. In this way, the binding energy can be tuned by the external fields and red-or blue-shifted with respect to the static binding energy. In the nonresonant polaron region, a magnetopolaron correction that includes the effects of photon process is observed. In the resonant polaron region, moreover, the resonant magnetopolaron effect accompanied by the emission and absorption of a single photon is distinctly observed. This can be modulated to be far away from the reststrahlen band. The intriguing findings of this paper can be observed experimentally and, in turn, provide a way to measure the strength of the electron-phonon interaction.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000426041900004 Publication Date (up) 2018-02-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 9 Open Access  
  Notes ; This work was supported by the National Natural Science Foundation of China (Grants No. 11404214 and No. 11455015) and the China Scholarship Council (CSC), Anhui Provincial Natural Science Foundation (Grant No. 1408085QA13), Key Projects of Anhui Provincial Department of Education (Grants No. KJ2017A406 and No. KJ2017A401). B.V.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a postdoctoral fellowship and M.V.d.D. was financially supported by the Research Science Foundation-Flanders (FWO-Vl) through a doctoral fellowship. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:149906UA @ admin @ c:irua:149906 Serial 4942  
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Author De Clercq, M.; Moors, K.; Sankaran, K.; Pourtois, G.; Dutta, S.; Adelmann, C.; Magnus, W.; Sorée, B. url  doi
openurl 
  Title Resistivity scaling model for metals with conduction band anisotropy Type A1 Journal article
  Year 2018 Publication Physical review materials Abbreviated Journal  
  Volume 2 Issue 3 Pages 033801  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract It is generally understood that the resistivity of metal thin films scales with film thickness mainly due to grain boundary and boundary surface scattering. Recently, several experiments and ab initio simulations have demonstrated the impact of crystal orientation on resistivity scaling. The crystal orientation cannot be captured by the commonly used resistivity scaling models and a qualitative understanding of its impact is currently lacking. In this work, we derive a resistivity scaling model that captures grain boundary and boundary surface scattering as well as the anisotropy of the band structure. The model is applied to Cu and Ru thin films, whose conduction bands are (quasi-) isotropic and anisotropic, respectively. After calibrating the anisotropy with ab initio simulations, the resistivity scaling models are compared to experimental resistivity data and a renormalization of the fitted grain boundary reflection coefficient can be identified for textured Ru.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication College Park, Md Editor  
  Language Wos 000426787600001 Publication Date (up) 2018-03-07  
  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 Open Access  
  Notes ; The authors acknowledge the support by the Fonds National de la Recherche Luxembourg (ATTRACT Grant No. 7556175). ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:149866UA @ admin @ c:irua:149866 Serial 4947  
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Author Gul, A.; Bacaksiz, C.; Unsal, E.; Akbali, B.; Tomak, A.; Zareie, H.M.; Sahin, H. doi  openurl
  Title Theoretical and experimental investigation of conjugation of 1,6-hexanedithiol on MoS2 Type A1 Journal article
  Year 2018 Publication Materials Research Express Abbreviated Journal Mater Res Express  
  Volume 5 Issue 3 Pages 036415  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We report an experimental and theoretical investigation of conjugation of 1,6-Hexaneditihiol (HDT) on MoS2 which is prepared by mixing MoS2 structure and HDT molecules in proper solvent. Raman spectra and the calculated phonon bands reveal that the HDT molecules bind covalently to MoS2. Surface morphology of MoS2/HDTstructure is changed upon conjugation ofHDTon MoS2 and characterized by using Scanning Electron Microscope (SEM). Density Functional Theory (DFT) based calculations show that HOMO-LUMO band gap of HDT is altered after the conjugation and two-S binding (handle-like) configuration is energetically most favorable among three different structures. This study displays that the facile thiol functionalization process of MoS2 is promising strategy for obtaining solution processable MoS2.  
  Address  
  Corporate Author Thesis  
  Publisher IOP Publishing Place of Publication Bristol Editor  
  Language Wos 000428781400003 Publication Date (up) 2018-03-07  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2053-1591 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 1.068 Times cited 2 Open Access  
  Notes ; Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid e-Infrastructure). HS acknowledges financial support from the TUBITAK under the project number 116C073. HS acknowledges support from Bilim Akademisi-The Science Academy, Turkey under the BAGEP program. ; Approved Most recent IF: 1.068  
  Call Number UA @ lucian @ c:irua:154607UA @ admin @ c:irua:154607 Serial 5133  
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Author Zhang, R.; Wu, Z.; Li, X.J.; Li, L.L.; Chen, Q.; Li, Y.-M.; Peeters, F.M. pdf  doi
openurl 
  Title Fano resonances in bilayer phosphorene nanoring Type A1 Journal article
  Year 2018 Publication Nanotechnology Abbreviated Journal Nanotechnology  
  Volume 29 Issue 21 Pages 215202  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Tunable transport properties and Fano resonances are predicted in a circular bilayer phosphorene nanoring. The conductance exhibits Fano resonances with varying incident energy and applied perpendicular magnetic field. These Fano resonance peaks can be accurately fitted with the well known Fano curves. When a magnetic field is applied to the nanoring, the conductance oscillates periodically with magnetic field which is reminiscent of the Aharonov-Bohm effect. Fano resonances are tightly related to the discrete states in the central nanoring, some of which are tunable by the magnetic field.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos 000428920200001 Publication Date (up) 2018-03-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0957-4484 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.44 Times cited 4 Open Access  
  Notes ; This work was supported by Grant No. 2017YFA0303400 from the National Key R&D Program of China, the Flemish Science Foundation, the grants No. 2016YFE0110000, No. 2015CB921503, and No. 2016YFA0202300 from the MOST of China, the NSFC (Grants Nos. 11504366, 11434010, 61674145 and 61774168) and CAS (Grants No. QYZDJ-SSW-SYS001). ; Approved Most recent IF: 3.44  
  Call Number UA @ lucian @ c:irua:150713UA @ admin @ c:irua:150713 Serial 4968  
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Author Pinto, N.; Rezvani, S.J.; Perali, A.; Flammia, L.; Milošević, M.V.; Fretto, M.; Cassiago, C.; De Leo, N. doi  openurl
  Title Dimensional crossover and incipient quantum size effects in superconducting niobium nanofilms Type A1 Journal article
  Year 2018 Publication Scientific reports Abbreviated Journal Sci Rep-Uk  
  Volume 8 Issue 8 Pages 4710  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Superconducting and normal state properties of Niobium nanofilms have been systematically investigated as a function of film thickness, on different substrates. The width of the superconductingto- normal transition for all films is remarkably narrow, confirming their high quality. The superconducting critical current density exhibits a pronounced maximum for thickness around 25 nm, marking the 3D-to-2D crossover. The magnetic penetration depth shows a sizeable enhancement for the thinnest films. Additional amplification effects of the superconducting properties have been obtained with sapphire substrates or squeezing the lateral size of the nanofilms. For thickness close to 20 nm we measured a doubled perpendicular critical magnetic field compared to its large thickness value, indicating shortening of the correlation length and the formation of small Cooper pairs. Our data analysis indicates an exciting interplay between quantum-size and proximity effects together with strong-coupling effects and the importance of disorder in the thinnest films, placing these nanofilms close to the BCS-BEC crossover regime.  
  Address  
  Corporate Author Thesis  
  Publisher Nature Publishing Group Place of Publication London Editor  
  Language Wos 000427588300011 Publication Date (up) 2018-03-12  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2045-2322 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 4.259 Times cited 37 Open Access  
  Notes ; We thank Antonio Bianconi, Mauro Doria and Vincenzo Lacquaniti for useful discussions. We acknowledge the collaboration with Federica Celegato for AFM analysis and Sara Quercetti for the electrical properties characterization. A. P. and N. P. acknowledge financial support from University of Camerino FAR project CESEMN. We also acknowledge the collaboration within the MultiSuper International Network (http://www.multisuper.org) for exchange of ideas and suggestions. ; Approved Most recent IF: 4.259  
  Call Number UA @ lucian @ c:irua:150843UA @ admin @ c:irua:150843 Serial 4965  
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Author Yagmurcukardes, M.; Bacaksiz, C.; Unsal, E.; Akbali, B.; Senger, R.T.; Sahin, H. url  doi
openurl 
  Title Strain mapping in single-layer two-dimensional crystals via Raman activity Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 11 Pages 115427  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract By performing density functional theory-based ab initio calculations, Raman-active phonon modes of single-layer two-dimensional (2D) materials and the effect of in-plane biaxial strain on the peak frequencies and corresponding activities of the Raman-active modes are calculated. Our findings confirm the Raman spectrum of the unstrained 2D crystals and provide expected variations in the Raman-active modes of the crystals under in-plane biaxial strain. The results are summarized as follows: (i) frequencies of the phonon modes soften (harden) under applied tensile (compressive) strains; (ii) the response of the Raman activities to applied strain for the in-plane and out-of-plane vibrational modes have opposite trends, thus, the built-in strains in the materials can be monitored by tracking the relative activities of those modes; (iii) in particular, the A peak in single-layer Si and Ge disappears under a critical tensile strain; (iv) especially in mono-and diatomic single layers, the shift of the peak frequencies is a stronger indication of the strain rather than the change in Raman activities; (v) Raman-active modes of single-layer ReX2 (X = S, Se) are almost irresponsive to the applied strain. Strain-induced modifications in the Raman spectrum of 2D materials in terms of the peak positions and the relative Raman activities of the modes could be a convenient tool for characterization.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000427799300006 Publication Date (up) 2018-03-19  
  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 21 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 Project No. 116C073. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:150840UA @ admin @ c:irua:150840 Serial 4979  
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Author Andelkovic, M.; Covaci, L.; Peeters, F.M. doi  openurl
  Title DC conductivity of twisted bilayer graphene: Angle-dependent transport properties and effects of disorder Type A1 Journal article
  Year 2018 Publication Physical review materials Abbreviated Journal  
  Volume 2 Issue 3 Pages 034004  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The in-plane dc conductivity of twisted bilayer graphene is calculated using an expansion of the real-space Kubo-Bastin conductivity in terms of Chebyshev polynomials. We investigate within a tight-binding approach the transport properties as a function of rotation angle, applied perpendicular electric field, and vacancy disorder. We find that for high-angle twists, the two layers are effectively decoupled, and the minimum conductivity at the Dirac point corresponds to double the value observed in monolayer graphene. This remains valid even in the presence of vacancies, hinting that chiral symmetry is still preserved. On the contrary, for low twist angles, the conductivity at the Dirac point depends on the twist angle and is not protected in the presence of disorder. Furthermore, for low angles and in the presence of an applied electric field, we find that the chiral boundary states emerging between AB and BA regions contribute to the dc conductivity, despite the appearance of localized states in the AA regions. The results agree qualitatively with recent transport experiments in low-angle twisted bilayer graphene.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication College Park, Md Editor  
  Language Wos 000427822700002 Publication Date (up) 2018-03-20  
  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 27 Open Access  
  Notes ; We acknowledge financial support from the graphene FLAG-ERA project TRANS2DTMD. ; Approved Most recent IF: NA  
  Call Number UA @ lucian @ c:irua:150838UA @ admin @ c:irua:150838 Serial 4964  
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Author Mei, H.; Xu, W.; Wang, C.; Yuan, H.; Zhang, C.; Ding, L.; Zhang, J.; Deng, C.; Wang, Y.; Peeters, F.M. pdf  url
doi  openurl
  Title Terahertz magneto-optical properties of bi- and tri-layer graphene Type A1 Journal article
  Year 2018 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat  
  Volume 30 Issue 17 Pages 175701  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Magneto-optical (MO) properties of bi- and tri-layer graphene are investigated utilizing terahertz time-domain spectroscopy (THz TDS) in the presence of a strong magnetic field at room-temperature. In the Faraday configuration and applying optical polarization measurements, we measure the real and imaginary parts of the longitudinal and transverse MO conductivities of different graphene samples. The obtained experimental data fits very well with the classical MO Drude formula. Thus, we are able to obtain the key sample and material parameters of bi- and tri-layer graphene, such as the electron effective mass, the electronic relaxation time and the electron density. It is found that in high magnetic fields the electronic relaxation time tau for bi- and tri-layer graphene increases with magnetic field B roughly in a form tau similar to B-2. Most importantly, we obtain the electron effective mass for bi- and tri-layer graphene at room-temperature under non-resonant conditions. This work shows how the advanced THz MO techniques can be applied for the investigation into fundamental physics properties of atomically thin 2D electronic systems.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000429329500001 Publication Date (up) 2018-03-20  
  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 11 Open Access  
  Notes ; This work was supported by the National Natural Science Foundation of China (11574319, 11304317, 11304272), the Ministry of Science and Technology of China (2011YQ130018), the Center of Science and Technology of Hefei Academy of Science, the Department of Science and Technology of Yunnan Province, and by the Chinese Academy of Sciences. ; Approved Most recent IF: 2.649  
  Call Number UA @ lucian @ c:irua:150715UA @ admin @ c:irua:150715 Serial 4983  
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Author Cavalcante, L.S.R.; Chaves, A.; Van Duppen, B.; Peeters, F.M.; Reichman, D.R. pdf  url
doi  openurl
  Title Electrostatics of electron-hole interactions in van der Waals heterostructures Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 12 Pages 125427  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The role of dielectric screening of electron-hole interaction in van der Waals heterostructures is theoretically investigated. A comparison between models available in the literature for describing these interactions is made and the limitations of these approaches are discussed. A simple numerical solution of Poisson's equation for a stack of dielectric slabs based on a transfer matrix method is developed, enabling the calculation of the electron-hole interaction potential at very low computational cost and with reasonable accuracy. Using different potential models, direct and indirect exciton binding energies in these systems are calculated within Wannier-Mott theory, and a comparison of theoretical results with recent experiments on excitons in two-dimensional materials is discussed.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000427983700007 Publication Date (up) 2018-03-21  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 22 Open Access  
  Notes Discussions with A. Chernikov and A. Raja are gratefully acknowledged. This work has been financially supported by CNPq, through the PRONEX/FUNCAP, PQ, and Science Without Borders programs, and the FWO-CNPq bilateral program between Brazil and Flanders. B.V.D. acknowledges support from the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. D.R.R. was supported by NSF CHE-1464802. Approved Most recent IF: 3.836  
  Call Number CMT @ cmt @c:irua:150835UA @ admin @ c:irua:150835 Serial 4953  
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Author Nakhaee, M.; Ketabi, S.A.; Peeters, F.M. url  doi
openurl 
  Title Tight-binding model for borophene and borophane Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 12 Pages 125424  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Starting from the simplified linear combination of atomic orbitals method in combination with first-principles calculations, we construct a tight-binding (TB) model in the two-centre approximation for borophene and hydrogenated borophene (borophane). The Slater and Koster approach is applied to calculate the TB Hamiltonian of these systems. We obtain expressions for the Hamiltonian and overlap matrix elements between different orbitals for the different atoms and present the SK coefficients in a nonorthogonal basis set. An anisotropic Dirac cone is found in the band structure of borophane. We derive a Dirac low-energy Hamiltonian and compare the Fermi velocities with that of graphene.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000427983700004 Publication Date (up) 2018-03-21  
  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 45 Open Access  
  Notes ; Discussions with Dr. Vahid Derakhshan and M. A. M. Keshtan are gratefully acknowledged. This paper is supported by the Methusalem program of the Flemish government and the FLAT-ERA Project TRANS-2D-TMD. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:150836UA @ admin @ c:irua:150836 Serial 4987  
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Author Kocabas, T.; Cakir, D.; Gulseren, O.; Ay, F.; Perkgoz, N.K.; Sevik, C. doi  openurl
  Title A distinct correlation between the vibrational and thermal transport properties of group VA monolayer crystals Type A1 Journal article
  Year 2018 Publication Nanoscale Abbreviated Journal  
  Volume 10 Issue 16 Pages 7803-7812  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract The investigation of thermal transport properties of novel two-dimensional materials is crucially important in order to assess their potential to be used in future technological applications, such as thermoelectric power generation. In this respect, the lattice thermal transport properties of the monolayer structures of group VA elements (P, As, Sb, Bi, PAs, PSb, PBi, AsSb, AsBi, SbBi, P3As1, P3Sb1, P1As3, and As3Sb1) with a black phosphorus like puckered structure were systematically investigated by first-principles calculations and an iterative solution of the phonon Boltzmann transport equation. Phosphorene was found to have the highest lattice thermal conductivity, , due to its low average atomic mass and strong interatomic bonding character. As a matter of course, anisotropic was obtained for all the considered materials, owing to anisotropy in frequency values and phonon group velocities calculated for these structures. However, the determined linear correlation between the anisotropy in the values of P, As, and Sb is significant. The results corresponding to the studied compound structures clearly point out that thermal (electronic) conductivity of pristine monolayers might be suppressed (improved) by alloying them with the same group elements. For instance, the room temperature of PBi along the armchair direction was predicted to be as low as 1.5 W m(-1) K-1, whereas that of P was predicted to be 21 W m(-1) K-1. In spite of the apparent differences in structural and vibrational properties, we peculiarly revealed an intriguing correlation between the values of all the considered materials as = c(1) + c(2)/m(2), in particular along the zigzag direction. Furthermore, our calculations on compound structures clearly showed that the thermoelectric potential of these materials can be improved by suppressing their thermal properties. The presence of ultra-low values and high electrical conductivity (especially along the armchair direction) makes this class of monolayers promising candidates for thermoelectric applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000431030000054 Publication Date (up) 2018-03-22  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364; 2040-3372 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:193785 Serial 7388  
Permanent link to this record
 

 
Author Mulkers, J.; Van Waeyenberge, B.; Milošević, M.V. url  doi
openurl 
  Title Tunable Snell's law for spin waves in heterochiral magnetic films Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 10 Pages 104422  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Thin ferromagnetic films with an interfacially induced DMI exhibit nontrivial asymmetric dispersion relations that lead to unique and useful magnonic properties. Here we derive an analytical expression for the magnon propagation angle within the micromagnetic framework and show how the dispersion relation can be approximated with a comprehensible geometrical interpretation in the k space of the propagation of spin waves. We further explore the refraction of spin waves at DMI interfaces in heterochiral magnetic films, after deriving a generalized Snell's law tunable by an in-plane magnetic field, that yields analytical expressions for critical incident angles. The found asymmetric Brewster angles at interfaces of regions with different DMI strengths, adjustable by magnetic field, support the conclusion that heterochiral ferromagnetic structures are an ideal platform for versatile spin-wave guides.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000428238600006 Publication Date (up) 2018-03-26  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 20 Open Access  
  Notes This work was supported by the Research Foundation- Flanders (FWO-Vlaanderen) through Project No. G098917N. Approved Most recent IF: 3.836  
  Call Number CMT @ cmt @c:irua:150118UA @ admin @ c:irua:150118 Serial 4915  
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Author Kong, X.; Li, L.; Leenaerts, O.; Wang, W.; Liu, X.-J.; Peeters, F.M. url  doi
openurl 
  Title Quantum anomalous Hall effect in a stable 1T-YN2 monolayer with a large nontrivial bandgap and a high Chern number Type A1 Journal article
  Year 2018 Publication Nanoscale Abbreviated Journal Nanoscale  
  Volume 10 Issue 17 Pages 8153-8161  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract The quantum anomalous Hall (QAH) effect is a topologically nontrivial phase, characterized by a non-zero Chern number defined in the bulk and chiral edge states in the boundary. Using first-principles calculations, we demonstrate the presence of the QAH effect in a 1T-YN2 monolayer, which was recently predicted to be a Dirac half metal without spin-orbit coupling (SOC). We show that the inclusion of SOC opens up a large nontrivial bandgap of nearly 0.1 eV in the electronic band structure. This results in the nontrivial bulk topology, which is confirmed by the calculation of Berry curvature, anomalous Hall conductance and the presence of chiral edge states. Remarkably, a QAH phase of high Chern number C = 3 is found, and there are three corresponding gapless chiral edge states emerging inside the bulk gap. Different substrates are also chosen to study the possible experimental realization of the 1T-YN2 monolayer, while retaining its nontrivial topological properties. Our results open a new avenue in searching for QAH insulators with high temperature and high Chern numbers, which can have nontrivial practical applications.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Cambridge Editor  
  Language Wos 000432261400033 Publication Date (up) 2018-03-28  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 7.367 Times cited 28 Open Access  
  Notes ; This work was supported by the Ministry of Science and Technology of China (MOST) (Grant No. 2016YFA0301604), the National Natural Science Foundation of China (NSFC) (No. 11574008), the Thousand-Young-Talent Program of China, 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. W. Wang acknowledges financial support from the National Natural Science Foundation of China (Grant No. 11404214) and the China Scholarship Council (CSC). ; Approved Most recent IF: 7.367  
  Call Number UA @ lucian @ c:irua:151519UA @ admin @ c:irua:151519 Serial 5040  
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Author Korneychuk, S.; Partoens, B.; Guzzinati, G.; Ramaneti, R.; Derluyn, J.; Haenen, K.; Verbeeck, J. pdf  url
doi  openurl
  Title Exploring possibilities of band gap measurement with off-axis EELS in TEM Type A1 Journal article
  Year 2018 Publication Ultramicroscopy Abbreviated Journal Ultramicroscopy  
  Volume 189 Issue 189 Pages 76-84  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract A technique to measure the band gap of dielectric materials with high refractive index by means of energy electron loss spectroscopy (EELS) is presented. The technique relies on the use of a circular (Bessel) aperture and suppresses Cherenkov losses and surface-guided light modes by enforcing a momentum transfer selection. The technique also strongly suppresses the elastic zero loss peak, making the acquisition, interpretation and signal to noise ratio of low loss spectra considerably better, especially for excitations in the first few eV of the EELS spectrum. Simulations of the low loss inelastic electron scattering probabilities demonstrate the beneficial influence of the Bessel aperture in this setup even for high accelerating voltages. The importance of selecting the optimal experimental convergence and collection angles is highlighted. The effect of the created off-axis acquisition conditions on the selection of the transitions from valence to conduction bands is discussed in detail on a simplified isotropic two band model. This opens the opportunity for deliberately selecting certain transitions by carefully tuning the microscope parameters. The suggested approach is experimentally demonstrated and provides good signal to noise ratio and interpretable band gap signals on reference samples of diamond, GaN and AlN while offering spatial resolution in the nm range. (C) 2018 Elsevier B.V. All rights reserved.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Amsterdam Editor  
  Language Wos 000432868500008 Publication Date (up) 2018-03-29  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0304-3991 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.843 Times cited 7 Open Access OpenAccess  
  Notes ; S.K., B.P. and J.V. acknowledge funding from the “Geconcentreerde Onderzoekacties” (GOA) project “Solarpaint” of the University of Antwerp. S.K. and J.V. also acknowledge the FWO-Vlaanderen for financial support under contract G.0044.13N 'Charge ordering'. Financial support via the Methusalem “NANO” network is acknowledged. GG acknowledges support from a postdoctoral fellowship grant from the Fonds Wetenschappelijk Onderzoek-Vlaanderen (FWO). ; Approved Most recent IF: 2.843  
  Call Number UA @ lucian @ c:irua:151472UA @ admin @ c:irua:151472 Serial 5026  
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Author Hu, S.; Gopinadhan, K.; Rakowski, A.; Neek-Amal, M.; Heine, T.; Grigorieva, I.V.; Haigh, S.J.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M. pdf  doi
openurl 
  Title Transport of hydrogen isotopes through interlayer spacing in van der Waals crystals Type A1 Journal article
  Year 2018 Publication Nature nanotechnology Abbreviated Journal Nat Nanotechnol  
  Volume 13 Issue 6 Pages 468-+  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract Atoms start behaving as waves rather than classical particles if confined in spaces commensurate with their de Broglie wavelength. At room temperature this length is only about one angstrom even for the lightest atom, hydrogen. This restricts quantum-confinement phenomena for atomic species to the realm of very low temperatures(1-5). Here, we show that van der Waals gaps between atomic planes of layered crystals provide angstrom-size channels that make quantum confinement of protons apparent even at room temperature. Our transport measurements show that thermal protons experience a notably higher barrier than deuterons when entering van der Waals gaps in hexagonal boron nitride and molybdenum disulfide. This is attributed to the difference in the de Broglie wavelengths of the isotopes. Once inside the crystals, transport of both isotopes can be described by classical diffusion, albeit with unexpectedly fast rates comparable to that of protons in water. The demonstrated angstrom-size channels can be exploited for further studies of atomistic quantum confinement and, if the technology can be scaled up, for sieving hydrogen isotopes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000434715700015 Publication Date (up) 2018-04-04  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1748-3387; 1748-3395 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 38.986 Times cited 32 Open Access  
  Notes ; The authors acknowledge support from the Lloyd's Register Foundation, EPSRC – EP/N010345/1, the European Research Council ARTIMATTER project – ERC-2012-ADG and from Graphene Flagship. M.L.-H. acknowledges a Leverhulme Early Career Fellowship. ; Approved Most recent IF: 38.986  
  Call Number UA @ lucian @ c:irua:152014UA @ admin @ c:irua:152014 Serial 5046  
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Author Sarikurt, S.; Çakir, D.; Keceli, M.; Sevik, C. doi  openurl
  Title The influence of surface functionalization on thermal transport and thermoelectric properties of MXene monolayers Type A1 Journal article
  Year 2018 Publication Nanoscale Abbreviated Journal  
  Volume 10 Issue 18 Pages 8859-8868  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract The newest members of a two-dimensional material family, involving transition metal carbides and nitrides (called MXenes), have garnered increasing attention due to their tunable electronic and thermal properties depending on the chemical composition and functionalization. This flexibility can be exploited to fabricate efficient electrochemical energy storage (batteries) and energy conversion (thermoelectric) devices. In this study, we calculated the Seebeck coefficients and lattice thermal conductivity values of oxygen terminated M2CO2 (where M = Ti, Zr, Hf, Sc) monolayer MXene crystals in two different functionalization configurations (model-II (MD-II) and model-III (MD-III)), using density functional theory and Boltzmann transport theory. We estimated the thermoelectric figure-of-merit, zT, of these materials by two different approaches, as well. First of all, we found that the structural model (i.e. adsorption site of oxygen atom on the surface of MXene) has a paramount impact on the electronic and thermoelectric properties of MXene crystals, which can be exploited to engineer the thermoelectric properties of these materials. The lattice thermal conductivity kappa(l), Seebeck coefficient and zT values may vary by 40% depending on the structural model. The MD-III configuration always has the larger band gap, Seebeck coefficient and zT, and smaller kappa(l) as compared to the MD-II structure due to a larger band gap, highly flat valence band and reduced crystal symmetry in the former. The MD-III configuration of Ti2CO2 and Zr2CO2 has the lowest kappa(l) as compared to the same configuration of Hf2CO2 and Sc2CO2. Among all the considered structures, the MD-II configuration of Hf2CO2 has the highest kappa(l), and Ti2CO2 and Zr2CO2 in the MD-III configuration have the lowest kappa(l). For instance, while the band gap of the MD-II configuration of Ti2CO2 is 0.26 eV, it becomes 0.69 eV in MD-III. The zT(max) value may reach up to 1.1 depending on the structural model of MXene.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000432096400055 Publication Date (up) 2018-04-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2040-3364; 2040-3372 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:193788 Serial 8654  
Permanent link to this record
 

 
Author Flammia, L.; Zhang, L.-F.; Covaci, L.; Perali, A.; Milošević, M.V. url  doi
openurl 
  Title Superconducting nanoribbon with a constriction : a quantum-confined Josephson junction Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 13 Pages 134514  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Extended defects are known to strongly affect nanoscale superconductors. Here, we report the properties of superconducting nanoribbons with a constriction formed between two adjacent step edges by solving the Bogoliubov-de Gennes equations self-consistently in the regime where quantum confinement is important. Since the quantum resonances of the superconducting gap in the constricted area are different from the rest of the nanoribbon, such constriction forms a quantum-confined S-S'-S Josephson junction, with a broadly tunable performance depending on the length and width of the constriction with respect to the nanoribbon, and possible gating. These findings provide an intriguing approach to further tailor superconducting quantum devices where Josephson effect is of use.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000430161500004 Publication Date (up) 2018-04-17  
  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 7 Open Access  
  Notes ; This work was supported by the Research Foundation Flanders (FWO-Vlaanderen), the Special Research Funds of the University of Antwerp (TOPBOF), the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001), the MultiSuper network, and the EU-COST NANOCOHYBRI action CA16218. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:150754UA @ admin @ c:irua:150754 Serial 4980  
Permanent link to this record
 

 
Author Demirtas, M.; Odaci, C.; Perkgoz, N.K.; Sevik, C.; Ay, F. doi  openurl
  Title Low Loss Atomic Layer Deposited Al2O3 Waveguides for Applications in On-Chip Optical Amplifiers Type A1 Journal article
  Year 2018 Publication IEEE journal of selected topics in quantum electronics Abbreviated Journal  
  Volume 24 Issue 4 Pages 3100508  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We present the growth and optimization of ultralow loss Si-based Al2O3 planar waveguides, which have a high potential to boost the performance of rare-earth ion doped waveguide devices operating at visible and C-band wavelength ranges. The planar waveguide structures are grown using thermal atomic layer deposition. Systematic characterization of the obtained thin films is performed by spectroscopic ellipsometry, X-ray diffraction, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy analyses, and the optimum parameters are identified. The optical loss measurements for both transverse electric (TE) and transverse magnetic polarized light at 633, 829, and 1549 nm are performed. The lowest propagation loss value of 0.04 +/- 0.02 dB/cm for the Al2O3 waveguides for TE polarization at 1549 nm is demonstrated.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000431396300001 Publication Date (up) 2018-04-18  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1077-260x 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:193780 Serial 8187  
Permanent link to this record
 

 
Author Li, L.L.; Partoens, B.; Peeters, F.M. url  doi
openurl 
  Title Tuning the electronic properties of gated multilayer phosphorene : a self-consistent tight-binding study Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 15 Pages 155424  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract By taking account of the electric-field-induced charge screening, a self-consistent calculation within the framework of the tight-binding approach is employed to obtain the electronic band structure of gated multilayer phosphorene and the charge densities on the different phosphorene layers. We find charge density and screening anomalies in single-gated multilayer phosphorene and electron-hole bilayers in dual-gated multilayer phosphorene. Due to the unique puckered lattice structure, both intralayer and interlayer charge screenings are important in gated multilayer phosphorene. We find that the electric-field tuning of the band structure of multilayer phosphorene is distinctively different in the presence and absence of charge screening. For instance, it is shown that the unscreened band gap of multilayer phosphorene decreases dramatically with increasing electric-field strength. However, in the presence of charge screening, the magnitude of this band-gap decrease is significantly reduced and the reduction depends strongly on the number of phosphorene layers. Our theoretical results of the band-gap tuning are compared with recent experiments and good agreement is found.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000430459400005 Publication Date (up) 2018-04-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 26 Open Access  
  Notes ; This work was financially supported by the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:150752UA @ admin @ c:irua:150752 Serial 4988  
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Author Rios, P.L.; Perali, A.; Needs, R.J.; Neilson, D. doi  openurl
  Title Evidence from quantum Monte Carlo simulations of large-gap superfluidity and BCS-BEC crossover in double electron-hole layers Type A1 Journal article
  Year 2018 Publication Physical review letters Abbreviated Journal Phys Rev Lett  
  Volume 120 Issue 17 Pages 177701  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We report quantum Monte Carlo evidence of the existence of large gap superfluidity in electron-hole double layers over wide density ranges. The superfluid parameters evolve from normal state to BEC with decreasing density, with the BCS state restricted to a tiny range of densities due to the strong screening of Coulomb interactions, which causes the gap to rapidly become large near the onset of superfluidity. The superfluid properties exhibit similarities to ultracold fermions and iron-based superconductors, suggesting an underlying universal behavior of BCS-BEC crossovers in pairing systems.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication New York, N.Y. Editor  
  Language Wos 000430547800002 Publication Date (up) 2018-04-23  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0031-9007 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 8.462 Times cited 11 Open Access  
  Notes ; The authors thank G. Baym, M. Bonitz, and G. Senatore for useful discussions. A. P. and D. N. acknowledge financial support from University of Camerino FAR project CESEMN and from the Italian MIUR through the PRIN 2015 program under Contract No. 2015C5SEJJ001. R. J. N. acknowledges financial support from the Engineering and Physical Sciences Research Council, U.K., under Grant No. EP/ P034616/1. P. L. R. acknowledges financial support from the Max-Planck Society. Computational resources have been provided by the High Performance Computing Service of the University of Cambridge and by the Max-Planck Institute for Solid State Research. ; Approved Most recent IF: 8.462  
  Call Number UA @ lucian @ c:irua:150750UA @ admin @ c:irua:150750 Serial 4967  
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Author de Aquino, B.R.H.; Ghorbanfekr-Kalashami, H.; Neek-Amal, M.; Peeters, F.M. url  doi
openurl 
  Title Electrostrictive behavior of confined water subjected to GPa pressure Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 14 Pages 144111  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Water inside a nanocapillary exhibits unconventional structural and dynamical behavior due to its ordered structure. The confining walls, density, and lateral pressures control profoundly the microscopic structure of trapped water. Here we study the electrostriction of confined water subjected to pressures of the order of GPa for two different setups: (i) a graphene nanochannel containing a constant number of water molecules independent of the height of the channel, (ii) an open nanochannel where water molecules can be exchanged with those in a reservoir. For the former case, a square-rhombic structure of confined water is formed when the height of the channel is d = 6.5 angstrom having a density of rho = 1.42 g cm(-3). By increasing the height of the channel, a transition from a flat to a buckled state occurs, whereas the density rapidly decreases and reaches the bulk density for d congruent to 8.5 angstrom. When a perpendicular electric field is applied, the water structure and the lateral pressure change. For strong electric fields (similar to 1 V/angstrom), the square-rhombic structure is destroyed. For an open setup, a solid phase of confined water consisting of an imperfect square-rhombic structure is formed. By applying a perpendicular field, the density and phase of confined water change. However, the density and pressure inside the channel decrease as compared to the first setup. Our study is closely related to recent experiments on confined water, and it reveals the sensitivity of the microscopic structure of confined water to the size of the channel, the external electric field, and the experimental setup.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000430809300002 Publication Date (up) 2018-04-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 6 Open Access  
  Notes ; This work was supported by the Fund for Scientific Research-Flanders (FWO-Vl) and the Methusalem programe. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:151574UA @ admin @ c:irua:151574 Serial 5023  
Permanent link to this record
 

 
Author Simchi, H.; Simchi, M.; Fardmanesh, M.; Peeters, F.M. pdf  url
doi  openurl
  Title Phase transition and field effect topological quantum transistor made of monolayer MoS2 Type A1 Journal article
  Year 2018 Publication Journal of physics : condensed matter Abbreviated Journal J Phys-Condens Mat  
  Volume 30 Issue 23 Pages 235303  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study topological phase transitions and topological quantum field effect transistor in monolayer molybdenum disulfide (MoS2) using a two-band Hamiltonian model. Without considering the quadratic (q(2)) diagonal term in the Hamiltonian, we show that the phase diagram includes quantum anomalous Hall effect, quantum spin Hall effect, and spin quantum anomalous Hall effect regions such that the topological Kirchhoff law is satisfied in the plane. By considering the q(2) diagonal term and including one valley, it is shown that MoS2 has a non-trivial topology, and the valley Chern number is non-zero for each spin. We show that the wave function is (is not) localized at the edges when the q(2) diagonal term is added (deleted) to (from) the spin-valley Dirac mass equation. We calculate the quantum conductance of zigzag MoS2 nanoribbons by using the nonequilibrium Green function method and show how this device works as a field effect topological quantum transistor.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication London Editor  
  Language Wos 000432821600001 Publication Date (up) 2018-04-26  
  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 2 Open Access  
  Notes ; ; Approved Most recent IF: 2.649  
  Call Number UA @ lucian @ c:irua:151457UA @ admin @ c:irua:151457 Serial 5035  
Permanent link to this record
 

 
Author Aierken, Y.; Sevik, C.; Gulseren, O.; Peeters, F.M.; Çakir, D. pdf  url
doi  openurl
  Title In pursuit of barrierless transition metal dichalcogenides lateral heterojunctions Type A1 Journal article
  Year 2018 Publication Nanotechnology Abbreviated Journal Nanotechnology  
  Volume 29 Issue 29 Pages 295202  
  Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)  
  Abstract There is an increasing need to understand interfaces between two-dimensional materials to realize an energy efficient boundary with low contact resistance and small heat dissipation. In this respect, we investigated the impact of charge and substitutional atom doping on the electronic transport properties of the hybrid metallic-semiconducting lateral junctions, formed between metallic (1T and 1T(d)) and semiconducting (1H) phases of MoS2 by means of first-principles and non-equilibrium Green function formalism based calculations. Our results clearly revealed the strong influence of the type of interface and crystallographic orientation of the metallic phase on the transport properties of these systems. The Schottky barrier height, which is the dominant mechanism for contact resistance, was found to be as large as 0.63 eV and 1.19 eV for holes and electrons, respectively. We found that armchair interfaces are more conductive as compared to zigzag termination due to the presence of the metallic Mo zigzag chains that are directed along the transport direction. In order to manipulate these barrier heights we investigated the influence of electron doping of the metallic part (i.e. 1T(d) -MoS2). We observed that the Fermi level of the hybrid system moves towards the conduction band of semiconducting 1H-MoS2 due to filling of 4d-orbital of metallic MoS2, and thus the Schottky barrier for electrons decreases considerably. Besides electron doping, we also investigated the effect of substitutional doping of metallic MoS2 by replacing Mo atoms with either Re or Ta. Due to its valency, Re (Ta) behaves as a donor (acceptor) and reduces the Schottky barrier for electrons (holes). Since Re and Ta based transition metal dichalcogenides crystallize in either the 1T(d) or 1T phase, substitutional doping with these atom favors the stabilization of the 1T(d) phase of MoS2. Co-doping of hybrid structure results in an electronic structure, which facilities easy dissociation of excitons created in the 1H part.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Bristol Editor  
  Language Wos 000432823800002 Publication Date (up) 2018-05-01  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0957-4484 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.44 Times cited 4 Open Access  
  Notes ; This work was supported by the bilateral project between the The Scientific and Technological Research Council of Turkey (TUBITAK) and FWO-Flanders, Flemish Science Foundation (FWO-VI) and the Methusalem foundation of the Flemish government. Computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TRGrid 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. We acknowledge the support from TUBITAK (Grant No. 115F024). ; Approved Most recent IF: 3.44  
  Call Number UA @ lucian @ c:irua:151451UA @ admin @ c:irua:151451 Serial 5029  
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Author Saberi-Pouya, S.; Vazifehshenas, T.; Saleh, M.; Farmanbar, M.; Salavati-fard, T. pdf  url
doi  openurl
  Title Plasmon modes in monolayer and double-layer black phosphorus under applied uniaxial strain Type A1 Journal article
  Year 2018 Publication Journal of applied physics Abbreviated Journal J Appl Phys  
  Volume 123 Issue 17 Pages 174301  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract We study the effects of an applied in-plane uniaxial strain on the plasmon dispersions of monolayer, bilayer, and double-layer black phosphorus structures in the long-wavelength limit within the linear elasticity theory. In the low-energy limit, these effects can be modeled through the change in the curvature of the anisotropic energy band along the armchair and zigzag directions. We derive analytical relations of the plasmon modes under uniaxial strain and show that the direction of the applied strain is important. Moreover, we observe that along the armchair direction, the changes of the plasmon dispersion with strain are different and larger than those along the zigzag direction. Using the analytical relations of two-layer phosphorene systems, we found that the strain-dependent orientation factor of layers could be considered as a means to control the variations of the plasmon energy. Furthermore, our study shows that the plasmonic collective modes are more affected when the strain is applied equally to the layers compared to the case in which the strain is applied asymmetrically to the layers. We also calculate the effect of strain on the drag resistivity in a double-layer black phosphorus structure and obtain that the changes in the plasmonic excitations, due to an applied strain, are mainly responsible for the predicted results. This study can be readily extended to other anisotropic two-dimensional materials. Published by AIP Publishing.  
  Address  
  Corporate Author Thesis  
  Publisher American Institute of Physics Place of Publication New York, N.Y. Editor  
  Language Wos 000431651600014 Publication Date (up) 2018-05-01  
  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 4 Open Access  
  Notes ; ; Approved Most recent IF: 2.068  
  Call Number UA @ lucian @ c:irua:151522UA @ admin @ c:irua:151522 Serial 5037  
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Author Saberi-Pouya, S.; Zarenia, M.; Perali, A.; Vazifehshenas, T.; Peeters, F.M. url  doi
openurl 
  Title High-temperature electron-hole superfluidity with strong anisotropic gaps in double phosphorene monolayers Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 17 Pages 174503  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Excitonic superfluidity in double phosphorene monolayers is investigated using the BCS mean-field equations. Highly anisotropic superfluidity is predicted where we found that the maximum superfluid gap is in the Bose-Einstein condensate (BEC) regime along the armchair direction and in the BCS-BEC crossover regime along the zigzag direction. We estimate the highest Kosterlitz-Thouless transition temperature with maximum value up to similar to 90 K with onset carrier densities as high as 4 x 10(12) cm(-2). This transition temperature is significantly larger than what is found in double electron-hole few-layers graphene. Our results can guide experimental research toward the realization of anisotropic condensate states in electron-hole phosphorene monolayers.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000431986100002 Publication Date (up) 2018-05-02  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 3.836 Times cited 17 Open Access  
  Notes ; We thank David Neilson for helpful discussions. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Methusalem program of the Flemish government and Iran Ministry of Science, Research and Technology. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:151533UA @ admin @ c:irua:151533 Serial 5028  
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Author Van der Donck, M.; Zarenia, M.; Peeters, F.M. url  doi
openurl 
  Title Excitons, trions, and biexcitons in transition-metal dichalcogenides : magnetic-field dependence Type A1 Journal article
  Year 2018 Publication Physical review B Abbreviated Journal Phys Rev B  
  Volume 97 Issue 19 Pages 195408  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The influence of a perpendicular magnetic field on the binding energy and structural properties of excitons, trions, and biexcitons in monolayers of semiconducting transition metal dichalcogenides (TMDs) is investigated. The stochastic variational method (SVM) with a correlated Gaussian basis is used to calculate the different properties of these few-particle systems. In addition, we present a simplified variational approach which supports the SVM results for excitons as a function of magnetic field. The exciton diamagnetic shift is compared with recent experimental results, and we extend this concept to trions and biexcitons. The effect of a local potential fluctuation, which we model by a circular potential well, on the binding energy of trions and biexcitons is investigated and found to significantly increase the binding of those excitonic complexes.  
  Address  
  Corporate Author Thesis  
  Publisher American Physical Society Place of Publication New York, N.Y Editor  
  Language Wos 000432024800005 Publication Date (up) 2018-05-07  
  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 36 Open Access  
  Notes ; This work was supported by the Research Foundation of Flanders (FWO-Vl) through an aspirant research grant for M.V.D.D. ; Approved Most recent IF: 3.836  
  Call Number UA @ lucian @ c:irua:151521UA @ admin @ c:irua:151521 Serial 5025  
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