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Author Zhao, X.N.; Xu, W.; Xiao, Y.M.; Van Duppen, B.
Title Spin polarization in monolayer MoS₂ in the presence of proximity-induced interactions Type A1 Journal article
Year (down) 2020 Publication International Journal Of Modern Physics C Abbreviated Journal Int J Mod Phys C
Volume 31 Issue 10 Pages 2050143
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract When monolayer (ML) MoS2 is placed on a substrate, the proximity-induced interactions such as the Rashba spin-orbit coupling (RSOC) and exchange interaction (EI) can be introduced. Thus, the electronic system can behave like a spintronic device. In this study, we present a theoretical study on how the presence of the RSCO and EI can lead to the band splitting, the lifting of the valley degeneracy and to the spin polarization in n- and p-type ML MoS2. We find that the maxima of the in-plane spin orientation in the conduction and valence bands in ML MoS2 depend on the Rashba parameter and the effective Zeeman field factor. At a fixed Rashba parameter, the minima of the split conduction band and the maxima of the split valence band along with the spin polarization in ML MoS2 can be tuned effectively by varying the effective Zeeman field factor. On the basis that the EI can be induced by placing the ML MoS2 on a ferromagnetic substrate or by magnetic doping in ML MoS2, we predict that the interesting spintronic effects can be observed in n- and p-type ML MoS2. This work can be helpful to gain an in-depth understanding of the basic physical properties of ML MoS2 for application in advanced electronic and optoelectronic devices.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000583803200009 Publication Date 2020-06-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0129-1831 ISBN Additional Links UA library record; WoS full record
Impact Factor 1.9 Times cited Open Access
Notes ; This work was supported by the Ministry of Science and Technology of China (Grant No. 2011YQ130018), Department of Science and Technology of Yunnan Province and by the Chinese Academy of Sciences. ; Approved Most recent IF: 1.9; 2020 IF: 1.171
Call Number UA @ admin @ c:irua:173635 Serial 6609
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Author Zhao, X.N.; Xu, W.; Xiao, Y.M.; Liu, J.; Van Duppen, B.; Peeters, F.M.
Title Terahertz optical Hall effect in monolayer MoS₂ in the presence of proximity-induced interactions Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 24 Pages 245412-12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The effect of proximity-induced interactions such as Rashba spin-orbit coupling (SOC) and exchange interaction on the electronic and optical properties of n-type monolayer (ML) MoS2 is investigated. We predict and demonstrate that the Rashba SOC can induce an in-plane spin splitting with terahertz (THz) energy, while the exchange interaction lifts the energy degeneracy in different valleys. Thus, spin polarization can be achieved in an n-type ML MoS2 and valley Hall or optical Hall effect can be observed using linearly polarized THz radiation. In such a case, the transverse optical conductivity sigma(xy) (omega) results from spin-flip transition within spin-split conduction bands and from the fact that contributions from electrons with different spin orientations in different valleys can no longer be canceled out. Interestingly, we find that for fixed effective Zeeman field (or exchange interaction) the lowest spin-split conduction band in ML MoS2 can be tuned from one in the K valley to another one in the K' valley by varying the Rashba parameter lambda(R). Therefore, by changing lambda(R) we can turn the sign of the spin polarization and Im sigma(xy) (omega) from positive to negative. Moreover, we find that the dominant contribution of the selection rules to sigma(xx)(omega) is from electrons in the K valley and to sigma(xy) (omega) is from electrons in the K' valley. These important and interesting theoretical findings can be helpful to experimental observation of the optical Hall effect in valleytronic systems using linearly polarized THz radiation fields.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000538715500011 Publication Date 2020-06-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 5 Open Access
Notes ; This work was supported by the National Natural Science Foundation of China (Grants No. U1930116, No. U1832153, and No. 11574319) and the Center of Science and Technology of Hefei Academy of Science (Grant No. 2016FXZY002). ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:170206 Serial 6622
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Author Conti, S.; Van der Donck, M.; Perali, A.; Peeters, F.M.; Neilson, D.
Title Doping-dependent switch from one- to two-component superfluidity in coupled electron-hole van der Waals heterostructures Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 22 Pages 220504-220506
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The hunt for high-temperature superfluidity has received new impetus from the discovery of atomically thin stable materials. Electron-hole superfluidity in coupled MoSe2-WSe2 monolayers is investigated using a mean-field multiband model that includes band splitting caused by strong spin-orbit coupling. This splitting leads to a large energy misalignment of the electron and hole bands which is strongly modified by interchanging the doping of the monolayers. The choice of doping determines if the superfluidity is tunable from one to two components.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000538941900002 Publication Date 2020-06-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 11 Open Access
Notes ; This work was partially supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl), the Methusalem Foundation, and the FLAG-ERA project TRANS2DTMD. We thank A. R. Hamilton and A. Vargas-Paredes for useful discussions. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:170201 Serial 6489
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Author Wozniak, T.; Faria, P.E., Jr.; Seifert, G.; Chaves, A.; Kunstmann, J.
Title Exciton g factors of van der Waals heterostructures from first-principles calculations Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 23 Pages 235408-235411
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract External fields are a powerful tool to probe optical excitations in a material. The linear energy shift of an excitation in a magnetic field is quantified by its effective g factor. Here we show how exciton g factors and their sign can be determined by converged first-principles calculations. We apply the method to monolayer excitons in semiconducting transition metal dichalcogenides and to interlayer excitons in MoSe2/WSe2 heterobilayers and obtain good agreement with recent experimental data. The precision of our method allows us to assign measured g factors of optical peaks to specific transitions in the band structure and also to specific regions of the samples. This revealed the nature of various, previously measured interlayer exciton peaks. We further show that, due to specific optical selection rules, g factors in van der Waals heterostructures are strongly spin and stacking-dependent. The calculation of orbital angular momenta requires the summation over hundreds of bands, indicating that for the considered two-dimensional materials the basis set size is a critical numerical issue. The presented approach can potentially be applied to a wide variety of semiconductors.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000537315100009 Publication Date 2020-06-03
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited Open Access
Notes Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:170219 Serial 7944
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Author McNaughton, B.; Milošević, M.V.; Perali, A.; Pilati, S.
Title Boosting Monte Carlo simulations of spin glasses using autoregressive neural networks Type A1 Journal article
Year (down) 2020 Publication Physical Review E Abbreviated Journal Phys Rev E
Volume 101 Issue 5 Pages 053312
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The autoregressive neural networks are emerging as a powerful computational tool to solve relevant problems in classical and quantum mechanics. One of their appealing functionalities is that, after they have learned a probability distribution from a dataset, they allow exact and efficient sampling of typical system configurations. Here we employ a neural autoregressive distribution estimator (NADE) to boost Markov chain Monte Carlo (MCMC) simulations of a paradigmatic classical model of spin-glass theory, namely, the two-dimensional Edwards-Anderson Hamiltonian. We show that a NADE can be trained to accurately mimic the Boltzmann distribution using unsupervised learning from system configurations generated using standard MCMC algorithms. The trained NADE is then employed as smart proposal distribution for the Metropolis-Hastings algorithm. This allows us to perform efficient MCMC simulations, which provide unbiased results even if the expectation value corresponding to the probability distribution learned by the NADE is not exact. Notably, we implement a sequential tempering procedure, whereby a NADE trained at a higher temperature is iteratively employed as proposal distribution in a MCMC simulation run at a slightly lower temperature. This allows one to efficiently simulate the spin-glass model even in the low-temperature regime, avoiding the divergent correlation times that plague MCMC simulations driven by local-update algorithms. Furthermore, we show that the NADE-driven simulations quickly sample ground-state configurations, paving the way to their future utilization to tackle binary optimization problems.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000535862000014 Publication Date 2020-05-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1539-3755; 1550-2376 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.366 Times cited 15 Open Access
Notes ; The authors thank I. Murray, G. Carleo, and F. RicciTersenghi for useful discussions. Financial support from the FAR2018 project titled “Supervised machine learning for quantum matter and computational docking” of the University of Camerino and from the Italian MIUR under Project No. PRIN2017 CEnTraL 20172H2SC4 is gratefully acknowledged. S.P. also acknowledges the CINECA award under the ISCRA initiative, for the availability of high performance computing resources and support. M.V.M. gratefully acknowledges the Visiting Professorship program at the University of Camerino that facilitated the collaboration in this work. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:170244 Serial 6463
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Author Bafekry, A.; Obeid, M.; Nguyen, C.; Bagheri Tagani, M.; Ghergherehchi, M.
Title Graphene hetero-multilayer on layered platinum mineral Jacutingaite (Pt₂HgSe₃): Van der Waals heterostructures with novel optoelectronic and thermoelectric performances Type A1 Journal article
Year (down) 2020 Publication Journal Of Materials Chemistry A Abbreviated Journal J Mater Chem A
Volume 8 Issue 26 Pages 13248-13260
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Motivated by the recent successful synthesis of the layered platinum mineral jacutingaite (Pt2HgSe3), we have studied the optoelectronic, mechanical, and thermoelectric properties of graphene hetero-multilayer on Pt(2)HgSe(3)monolayer (PHS) heterostructures (LG/PHS) by using first-principles calculations. PHS is a topological insulator with a band gap of about 160 meV with fully relativistic calculations; when graphene layers are stacked on PHS, a narrow band gap of similar to 10-15 meV opens. In the presence of gate-voltage and out-of plane strain,i.e.pressure, the electronic properties are modified; the Dirac-cone of graphene can be shifted upwards (downward) to a lower (higher) binding energy. The absorption spectrum shows two peaks, which are located around 216 nm (5.74 eV) and protracted to 490 nm (2.53 eV), indicating that PHS could absorb more visible light. Increasing the number of graphene layers on PHS has a positive impact on the UV-vis light absorption and gives a clear red-shift with enhanced absorption intensity. To investigate the electronic performance of the heterostructure, the electrical conductance and thermopower of a device composed of graphene layers and PHS is examined by a combination of DFT and Green function formalism. The number of graphene layers can significantly tune the thermopower and electrical conductance. This analysis reveals that the heterostructures not only significantly affect the electronic properties, but they can also be used as an efficient way to modulate the optic and thermoelectric properties.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000546391600032 Publication Date 2020-05-28
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2050-7488; 2050-7496 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 11.9 Times cited 20 Open Access
Notes ; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea Government (MSIT) (NRF-2017R1A2B2011989) and Vietnam National Foundation for Science and Technology Development (NAFOSTED) under grant number 103.01-2019.05. ; Approved Most recent IF: 11.9; 2020 IF: 8.867
Call Number UA @ admin @ c:irua:169755 Serial 6529
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Author Yan, X.F.; Chen, Q.; Li, L.L.; Guo, H.Z.; Peng, J.Z.; Peeters, F.M.
Title High performance piezotronic spin transistors using molybdenum disulfide nanoribbon Type A1 Journal article
Year (down) 2020 Publication Nano Energy Abbreviated Journal Nano Energy
Volume 75 Issue Pages 104953
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Two-dimensional (2D) materials are promising candidates for atomic-scale piezotronics and piezophototronics. Quantum edge states show fascinating fundamental physics such as nontrivial topological behavior and hold promising practical applications for low-power electronic devices. Here, using the tight-binding approach and quantum transport simulations, we investigate the piezotronic effect on the spin polarization of edge states in a zigzag-terminated monolayer MoS2 nanoribbon. We find that the strain-induced piezoelectric potential induces a phase transition of edge states from metal to semiconductor. However, in the presence of exchange field, edge states become semi-metallic with significant spin splitting and polarization that can be tuned by external strain. We show that quantum transport conductance exhibits a 100% spin polarization over a wide range of strain magnitudes. This effect is used in a propose prototype of piezotronic spin transistor. Our results provide a fundamental understanding of the piezotronic effect on edge states in zigzag monolayer MoS2 nanoribbons and are relevant for designing high-performance piezotronic spin devices.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000560729200011 Publication Date 2020-05-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2211-2855 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 17.6 Times cited 17 Open Access
Notes ; This work was supported by Hunan Provincial Natural Science Foundation of China (Nos. 2015JJ2040, 2018JJ2078), Scientific Research Fund of Hunan Provincial Education Department (19A106), and the Funeral Service Foundation (FWO-VI). ; Approved Most recent IF: 17.6; 2020 IF: 12.343
Call Number UA @ admin @ c:irua:171123 Serial 6535
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Author Van Pottelberge, R.
Title Comment on “Electron states for gapped pseudospin-1 fermions in the field of a charged impurity” Type Editorial
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 19 Pages 197102-197103
Keywords Editorial; Condensed Matter Theory (CMT)
Abstract In a recent paper [Phys. Rev. B 99, 155124 (2019)], the spectrum of a regularized Coulomb charge was studied in gapped pseudospin-1 systems generated by an alpha – T-3 lattice. The electronic spectrum was studied as a function of the impurity strength Z alpha. However, the results and conclusions on the behavior of the flatband states as a function of the impurity strength are incomplete. In this Comment, I argue that because of the dispersionless nature of the flatband, the states spread out under the influence of a charged impurity forming a continuous band of states. I support my arguments with explicit numerical calculations which show the emergence of a continuum of states.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000533793600004 Publication Date 2020-05-20
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 3.7 Times cited Open Access
Notes ; I would like to acknowledge very insightful discussions with the authors of the commented paper (V. P. Gusynin, E. V. Gorbar, and D. O. Oriekhov). F. M. Peeters is acknowledged for interesting discussions and proofreading. This research was supported by the Flemish Science Foundation through an aspirant research grant for R.V.P. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:169476 Serial 6472
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Author Dong, H.M.; Tao, Z.H.; Li, L.L.; Huang, F.; Xu, W.; Peeters, F.M.
Title Substrate dependent terahertz response of monolayer WS₂ Type A1 Journal article
Year (down) 2020 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 116 Issue 20 Pages 1-4
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We investigate experimentally the terahertz (THz) optoelectronic properties of monolayer (ML) tungsten disulfide (WS2) placed on different substrates using THz time-domain spectroscopy (TDS). We find that the THz optical response of n-type ML WS2 depends sensitively on the choice of the substrate. This dependence is found to be a consequence of substrate induced charge transfer, extra scattering centers, and electronic localization. Through fitting the experimental results with the Drude-Smith formula, we can determine the key sample parameters (e.g., the electronic relaxation time, electron density, and electronic localization factor) of ML WS2 on different substrates. The temperature dependence of these parameters is examined. Our results show that the THz TDS technique is an efficient non-contact method that can be utilized to characterize and investigate the optoelectronic properties of nano-devices based on ML WS2.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000536282300001 Publication Date 2020-05-20
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 4 Times cited 10 Open Access
Notes ; This work was supported by the Fundamental Research Funds for the Central Universities (Grant No. 2018GF09) and by the National Natural Science foundation of China (Nos. U1930116 and 11574319). ; Approved Most recent IF: 4; 2020 IF: 3.411
Call Number UA @ admin @ c:irua:170255 Serial 6620
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Author Griffin, E.; Mogg, L.; Hao, G.-P.; Kalon, G.; Bacaksiz, C.; Lopez-Polin, G.; Zhou, T.Y.; Guarochico, V.; Cai, J.; Neumann, C.; Winter, A.; Mohn, M.; Lee, J.H.; Lin, J.; Kaiser, U.; Grigorieva, I., V; Suenaga, K.; Ozyilmaz, B.; Cheng, H.-M.; Ren, W.; Turchanin, A.; Peeters, F.M.; Geim, A.K.; Lozada-Hidalgo, M.
Title Proton and Li-Ion permeation through graphene with eight-atom-ring defects Type A1 Journal article
Year (down) 2020 Publication Acs Nano Abbreviated Journal Acs Nano
Volume 14 Issue 6 Pages 7280-7286
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract Defect-free graphene is impermeable to gases and liquids but highly permeable to thermal protons. Atomic-scale defects such as vacancies, grain boundaries, and Stone-Wales defects are predicted to enhance graphene's proton permeability and may even allow small ions through, whereas larger species such as gas molecules should remain blocked. These expectations have so far remained untested in experiment. Here, we show that atomically thin carbon films with a high density of atomic-scale defects continue blocking all molecular transport, but their proton permeability becomes similar to 1000 times higher than that of defect-free graphene. Lithium ions can also permeate through such disordered graphene. The enhanced proton and ion permeability is attributed to a high density of eight-carbon-atom rings. The latter pose approximately twice lower energy barriers for incoming protons compared to that of the six-atom rings of graphene and a relatively low barrier of similar to 0.6 eV for Li ions. Our findings suggest that disordered graphene could be of interest as membranes and protective barriers in various Li-ion and hydrogen technologies.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000543744100086 Publication Date 2020-05-19
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1936-0851 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 17.1 Times cited 34 Open Access
Notes ; The work was supported by the Lloyd's Register Foundation, EPSRC-EP/N010345/1, the European Research Council, the Graphene Flagship, the Deutsche Forschungsgemeinschaft project TRR 234 “CataLight” (Project B7, Grant No. 364549901), and the research infrastructure Grant No. INST 275/25 7-1 FUGG. E.G. and L.M. acknowledge the EPSRC NowNANO programme for funding. ; Approved Most recent IF: 17.1; 2020 IF: 13.942
Call Number UA @ admin @ c:irua:170708 Serial 6586
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Author Nakhaee, M.; Ketabi, S.A.; Peeters, F.M.
Title Tight-binding studio : a technical software package to find the parameters of tight-binding Hamiltonian Type A1 Journal article
Year (down) 2020 Publication Computer Physics Communications Abbreviated Journal Comput Phys Commun
Volume 254 Issue Pages 107379-10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We present the Tight-Binding Studio (TB Studio) software package that calculates the different parameters of a tight-binding Hamiltonian from a set of Bloch energy bands obtained from first principle theories such as density functional theory, Hartree-Fock calculations or semi-empirical band-structure theory. This will be helpful for scientists who are interested in studying electronic and optical properties of structures using Green's function theory within the tight-binding approximation. TB Studio is a cross-platform application written in C++ with a graphical user interface design that is user-friendly and easy to work with. This software is powered by Linear Algebra Package C interface library for solving the eigenvalue problems and the standard high performance OpenGL graphic library for real time plotting. TB Studio and its examples together with the tutorials are available for download from tight-binding.com. Program summary Program Title: Tight-Binding Studio Program Files doi:http://dx.doi.org/10.17632/j6x5mwzm2d.1 Licensing provisions: LGPL Programming language: C++ External routines: BLAS, LAPACK, LAPACKE, wxWidgets, OpenGL, MathGL Nature of problem: Obtaining Tight-Binding Hamiltonian from a set of Bloch energy bands obtained from first-principles calculations. Solution method: Starting from the simplified LCAO method, a tight-binding model in the two-center approximation is constructed. The Slater and Koster (SK) approach is used to calculate the parameters of the TB Hamiltonian. By using non-linear fitting approaches the optimal values of the SK parameters are obtained such that the TB energy eigenvalues are as close as possible to those from first-principles calculations. We obtain the expression for the Hamiltonian and the overlap matrix elements between the different orbitals of the different atoms in an orthogonal or non-orthogonal basis set. (C) 2020 Elsevier B.V. All rights reserved.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000541251200030 Publication Date 2020-05-18
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0010-4655 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 6.3 Times cited 14 Open Access
Notes ; This work was supported by the Methusalem program of the Flemish government, Belgium and M. Nakhaee was supported by a BOF-fellowship (UAntwerpen), Belgium. ; Approved Most recent IF: 6.3; 2020 IF: 3.936
Call Number UA @ admin @ c:irua:170149 Serial 6630
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Author Reijniers, J.; Partoens, B.; Steckel, J.; Peremans, H.
Title HRTF measurement by means of unsupervised head movements with respect to a single fixed speaker Type A1 Journal article
Year (down) 2020 Publication Ieee Access Abbreviated Journal Ieee Access
Volume 8 Issue Pages 92287-92300
Keywords A1 Journal article; Mass communications; Engineering Management (ENM); Condensed Matter Theory (CMT); Co-Design of Cyber-Physical Systems (Cosys-Lab)
Abstract In a standard state-of-the-art measurement the head-related transfer function (HRTF) is obtained in an anechoic room with an elaborate setup involving multiple calibrated loudspeakers. In search for a simplified method that would open up the possibility for an HRTF measurement in a home environment, it has been suggested that this setup could be replaced with one with a single, fixed loudspeaker. In such a setup, the subject samples different directions by moving the head with respect to this loudspeaker, while the head movements are tracked in some way. In this paper, the feasibility of such an approach is studied. To this end, the HRTF is measured in an unmodified (non-anechoic) room by means of a single external speaker and a high resolution head tracking system. The differences between the dynamically obtained HRTF and the standard static HRTF are investigated, and are shown to be mostly due to variable torso reflections.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000539041600001 Publication Date 2020-05-15
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2169-3536 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.9 Times cited 4 Open Access
Notes ; This work was supported in part by the Research Foundation Flanders (FWO) under Grant G023619N, and in part by the Agency for Innovation and Entrepreneurship (VLAIO). ; Approved Most recent IF: 3.9; 2020 IF: 3.244
Call Number UA @ admin @ c:irua:170318 Serial 6539
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Author Kong, X.; Li, L.; Liang, L.; Peeters, F.M.; Liu, X.-J.
Title The magnetic, electronic, and light-induced topological properties in two-dimensional hexagonal FeX₂ (X=Cl, Br, I) monolayers Type A1 Journal article
Year (down) 2020 Publication Applied Physics Letters Abbreviated Journal Appl Phys Lett
Volume 116 Issue 19 Pages 192404-192405
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using Floquet-Bloch theory, we propose to realize chiral topological phases in two-dimensional (2D) hexagonal FeX2 (X=Cl, Br, I) monolayers under irradiation of circularly polarized light. Such 2D FeX2 monolayers are predicted to be dynamically stable and exhibit both ferromagnetic and semiconducting properties. To capture the full topological physics of the magnetic semiconductor under periodic driving, we adopt ab initio Wannier-based tight-binding methods for the Floquet-Bloch bands, with the light-induced bandgap closings and openings being obtained as the light field strength increases. The calculations of slabs with open boundaries show the existence of chiral edge states. Interestingly, the topological transitions with branches of chiral edge states changing from zero to one and from one to two by tuning the light amplitude are obtained, showing that the topological Floquet phase of high Chern number can be induced in the present Floquet-Bloch systems. Published under license by AIP Publishing.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000533500900001 Publication Date 2020-05-11
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 4 Times cited 13 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) (Nos. 11574008, 11761161003, 11825401, and 11921005), the Strategic Priority Research Program of Chinese Academy of Science (Grant No. XDB28000000), 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. This research also used resources of the Compute and Data Environment for Science (CADES) at the Oak Ridge National Laboratory, which was supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725. X.K. and L.L. also acknowledge the work conducted at the Center for Nanophase Materials Sciences, which is a U.S. Department of Energy Office of Science User Facility. ; Approved Most recent IF: 4; 2020 IF: 3.411
Call Number UA @ admin @ c:irua:169496 Serial 6623
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Author Gjerding, M.N.; Cavalcante, L.S.R.; Chaves, A.; Thygesen, K.S.
Title Efficient Ab initio modeling of dielectric screening in 2D van der Waals materials : including phonons, substrates, and doping Type A1 Journal article
Year (down) 2020 Publication Journal Of Physical Chemistry C Abbreviated Journal J Phys Chem C
Volume 124 Issue 21 Pages 11609-11616
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract The quantum electrostatic heterostructure (QEH) model allows for efficient computation of the dielectric screening properties of layered van der Waals (vdW)-bonded heterostructures in terms of the dielectric functions of the individual two-dimensional (2D) layers. Here, we extend the QEH model by including (1) contributions to the dielectric function from infrared active phonons in the 2D layers, (2) screening from homogeneous bulk substrates, and (3) intraband screening from free carriers in doped 2D semiconductor layers. We demonstrate the potential of the extended QEH model by calculating the dispersion of coupled phonons in multilayer stacks of hexagonal boron-nitride (hBN), the strong hybridization of plasmons and optical phonons in graphene/hBN heterostructures, the effect of substrate screening on the exciton series of monolayer MoS2, and the properties of hyperbolic plasmons in a doped phosphorene sheet. The new QEH code is distributed as a Python package with a simple command line interface and a comprehensive library of dielectric building blocks for the most common 2D materials, providing an efficient open platform for dielectric modeling of realistic vdW heterostructures.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000614615900022 Publication Date 2020-05-04
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 3.7 Times cited Open Access
Notes Approved Most recent IF: 3.7; 2020 IF: 4.536
Call Number UA @ admin @ c:irua:176187 Serial 7852
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Author Baskurt, M.; Yagmurcukardes, M.; Peeters, F.M.; Sahin, H.
Title Stable single-layers of calcium halides (CaX₂, X = F, Cl, Br, I) Type A1 Journal article
Year (down) 2020 Publication Journal Of Chemical Physics Abbreviated Journal J Chem Phys
Volume 152 Issue 16 Pages 164116-164118
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By means of density functional theory based first-principles calculations, the structural, vibrational, and electronic properties of 1H- and 1T-phases of single-layer CaX2 (X = F, Cl, Br, or I) structures are investigated. Our results reveal that both the 1H- and 1T-phases are dynamically stable in terms of their phonon band dispersions with the latter being the energetically favorable phase for all single-layers. In both phases of single-layer CaX2 structures, significant phonon softening occurs as the atomic radius increases. In addition, each structural phase exhibits distinctive Raman active modes that enable one to characterize either the phase or the structure via Raman spectroscopy. The electronic band dispersions of single-layer CaX2 structures reveal that all structures are indirect bandgap insulators with a decrease in bandgaps from fluorite to iodide crystals. Furthermore, the calculated linear elastic constants, in-plane stiffness, and Poisson ratio indicate the ultra-soft nature of CaX2 single-layers, which is quite important for their nanoelastic applications. Overall, our study reveals that with their dynamically stable 1T- and 1H-phases, single-layers of CaX2 crystals can be alternative ultra-thin insulators.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000531819100001 Publication Date 2020-04-29
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-9606 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 4.4 Times cited 10 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 TUBITAK under Project No. 117F095. H.S. acknowledges support from the Turkish Academy of Sciences under the GEBIP program. M.Y. was supported by a postdoctoral fellowship from the Flemish Science Foundation (FWO-Vl). ; Approved Most recent IF: 4.4; 2020 IF: 2.965
Call Number UA @ admin @ c:irua:169543 Serial 6615
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Author Bafekry, A.; Akgenc, B.; Ghergherehchi, M.; Peeters, F.M.
Title Strain and electric field tuning of semi-metallic character WCrCO₂ MXenes with dual narrow band gap Type A1 Journal article
Year (down) 2020 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat
Volume 32 Issue 35 Pages 355504-355508
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Motivated by the recent successful synthesis of double-M carbides, we investigate structural and electronic properties of WCrC and WCrCO2 monolayers and the effects of biaxial and out-of-plane strain and electric field using density functional theory. WCrC and WCrCO2 monolayers are found to be dynamically stable. WCrC is metallic and WCrCO2 display semi-metallic character with narrow band gap, which can be controlled by strain engineering and electric field. WCrCO2 monolayer exhibits a dual band gap which is preserved in the presence of an electric field. The band gap of WCrCO2 monolayer increases under uniaxial strain while it becomes metallic under tensile strain, resulting in an exotic 2D double semi-metallic behavior. Our results demonstrate that WCrCO2 is a new platform for the study of novel physical properties in two-dimensional Dirac materials and which may provide new opportunities to realize high-speed low-dissipation devices.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000539375800001 Publication Date 2020-04-29
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 2.7 Times cited 37 Open Access
Notes ; This work was supported by the National Research Foundation of Korea(NRF) Grant funded by the Korea government(MSIT)(NRF-2017R1A2B2011989). In addition, this work was supported by the Flemish Science Foundation (FW0-Vl). ; Approved Most recent IF: 2.7; 2020 IF: 2.649
Call Number UA @ admin @ c:irua:169756 Serial 6616
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Author Yagmurcukardes, M.; Peeters, F.M.
Title Stable single layer of Janus MoSO: strong out-of-plane piezoelectricity Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 15 Pages 155205-155208
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using density functional theory based first-principles calculations, we predict the dynamically stable 1H phase of a Janus single layer composed of S-Mo-O atomic layers. It is an indirect band gap semiconductor exhibiting strong polarization arising from the charge difference on the two surfaces. In contrast to 1H phases of MoS2 and MoO2, Janus MoSO is found to possess four Raman active phonon modes and a large out-of-plane piezoelectric coefficient which is absent in fully symmetric single layers of MoS2 and MoO2. We investigated the electronic and phononic properties under applied biaxial strain and found an electronic phase transition with tensile strain while the conduction band edge displays a shift when under compressive strain. Furthermore, single-layer MoSO exhibits phononic stability up to 5% of compressive and 11% of tensile strain with significant phonon shifts. The phonon instability is shown to arise from the soft in-plane and out-of-plane acoustic modes at finite wave vector. The large strain tolerance of Janus MoSO is important for nanoelastic applications. In view of the dynamical stability even under moderate strain, we expect that Janus MoSO can be fabricated in the common 1H phase with a strong out-of-plane piezoelectric coefficient.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000528507900003 Publication Date 2020-04-24
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 49 Open Access
Notes ; Computational resources were provided by the Flemish Supercomputer Center (VSC). M.Y. is supported by the Flemish Science Foundation (FWO-Vl) through a postdoctoral fellowship. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:169566 Serial 6614
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Author Bafekry, A.; Stampfl, C.; Peeters, F.M.
Title The electronic, optical, and thermoelectric properties of monolayer PbTe and the tunability of the electronic structure by external fields and defects Type A1 Journal article
Year (down) 2020 Publication Physica Status Solidi B-Basic Solid State Physics Abbreviated Journal Phys Status Solidi B
Volume Issue Pages 2000182-12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract First‐principles calculations, within the framework of density functional theory, are used to investigate the structural, electronic, optical, and thermoelectric properties of monolayer PbTe. The effect of layer thickness, electric field, strain, and vacancy defects on the electronic and magnetic properties is systematically studied. The results show that the bandgap decreases as the layer thickness increases from monolayer to bulk. With application of an electric field on bilayer PbTe, the bandgap decreases from 70 meV (0.2 V Å⁻¹) to 50 meV (1 V Å⁻¹) when including spin–orbit coupling (SOC). Application of uniaxial strain induces a direct‐to‐indirect bandgap transition for strain greater than +6%. In addition, the bandgap decreases under compressive biaxial strain (with SOC). The effect of vacancy defects on the electronic properties of PbTe is also investigated. Such vacancy defects turn PbTe into a ferromagnetic metal (single vacancy Pb) with a magnetic moment of 1.3 μB, and into an indirect semiconductor with bandgap of 1.2 eV (single Te vacancy) and 1.5 eV (double Pb + Te vacancy). In addition, with change of the Te vacancy concentration, a bandgap of 0.38 eV (5.55%), 0.43 eV (8.33%), and 0.46 eV (11.11%) is predicted.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000527679200001 Publication Date 2020-04-23
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0370-1972 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 1.6 Times cited 37 Open Access
Notes ; This work was supported by the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIT) (NRF-2017R1A2B2011989). In addition, this work was supported by the FLAG-ERA project 2DTRANS TMD and the Flemish Science Foundation (FWO-Vl). The authors are thankful for comments by Mohan Verma from the Computational Nanoionics Research Lab, Department of Applied Physics, Bhilai, India and to Francesco Buonocore from ENEA, Casaccia Research Centre, Rome, Italy. ; Approved Most recent IF: 1.6; 2020 IF: 1.674
Call Number UA @ admin @ c:irua:168730 Serial 6502
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Author Bekaert, J.; Khestanova, E.; Hopkinson, D.G.; Birkbeck, J.; Clark, N.; Zhu, M.; Bandurin, D.A.; Gorbachev, R.; Fairclough, S.; Zou, Y.; Hamer, M.; Terry, D.J.; Peters, J.J.P.; Sanchez, A.M.; Partoens, B.; Haigh, S.J.; Milošević, M.V.; Grigorieva, I., V
Title Enhanced superconductivity in few-layer TaS₂ due to healing by oxygenation Type A1 Journal article
Year (down) 2020 Publication Nano Letters Abbreviated Journal Nano Lett
Volume 20 Issue 5 Pages 3808-3818
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract When approaching the atomically thin limit, defects and disorder play an increasingly important role in the properties of two-dimensional (2D) materials. While defects are generally thought to negatively affect superconductivity in 2D materials, here we demonstrate the contrary in the case of oxygenation of ultrathin tantalum disulfide (TaS2). Our first-principles calculations show that incorporation of oxygen into the TaS2 crystal lattice is energetically favorable and effectively heals sulfur vacancies typically present in these crystals, thus restoring the electronic band structure and the carrier density to the intrinsic characteristics of TaS2. Strikingly, this leads to a strong enhancement of the electron-phonon coupling, by up to 80% in the highly oxygenated limit. Using transport measurements on fresh and aged (oxygenated) few-layer TaS2, we found a marked increase of the superconducting critical temperature (T-c) upon aging, in agreement with our theory, while concurrent electron microscopy and electron-energy loss spectroscopy confirmed the presence of sulfur vacancies in freshly prepared TaS2 and incorporation of oxygen into the crystal lattice with time. Our work thus reveals the mechanism by which certain atomic-scale defects can be beneficial to superconductivity and opens a new route to engineer T-c in ultrathin materials.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000535255300114 Publication Date 2020-04-20
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1530-6984 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 10.8 Times cited 16 Open Access
Notes ; This work was supported by Research Foundation-Flanders (FWO). J.Be. acknowledges support of a postdoctoral fellowship of the FWO. The computational resources and services used for the first-principles calculations in this work were provided by the VSC (Flemish Supercomputer Center), funded by the FWO and the Flemish Government-department EWI. S.J.H., D.H., and S.F. would like to thank the Engineering and Physical Sciences Research Council (EPSRC) U.K (grants EP/R031711/1, EP/P009050/1 and the Graphene NOWNANO CDT) and the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (grant agreement ERC-2016-STG-EvoluTEM-715502, the Hetero2D Synergy grant and EC-FET Graphene Flagship) for funding. We thank Diamond Light Source for access and support in use of the electron Physical Science Imaging Centre (Instrument E02 and proposal numbers EM19315 and MG21597) that contributed to the results presented here. ; Approved Most recent IF: 10.8; 2020 IF: 12.712
Call Number UA @ admin @ c:irua:170264 Serial 6507
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Author Marchetti, A.; Saniz, R.; Krishnan, D.; Rabbachin, L.; Nuyts, G.; De Meyer, S.; Verbeeck, J.; Janssens, K.; Pelosi, C.; Lamoen, D.; Partoens, B.; De Wael, K.
Title Unraveling the Role of Lattice Substitutions on the Stabilization of the Intrinsically Unstable Pb2Sb2O7Pyrochlore: Explaining the Lightfastness of Lead Pyroantimonate Artists’ Pigments Type A1 Journal article
Year (down) 2020 Publication Chemistry Of Materials Abbreviated Journal Chem Mater
Volume 32 Issue 7 Pages 2863-2873
Keywords A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation); Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
Abstract The pyroantimonate pigments Naples yellow and lead tin antimonate yellow are recognized as some of the most stable synthetic yellow pigments in the history of art. However, this exceptional lightfastness is in contrast with experimental evidence suggesting that this class of mixed oxides is of semiconducting nature. In this study the electronic structure and light-induced behavior of the lead pyroantimonate pigments were determined by means of a combined multifaceted analytical and computational approach (photoelectrochemical measurements, UV-vis diffuse reflectance spectroscopy, STEM-EDS, STEM-HAADF, and density functional theory calculations). The results demonstrate both the semiconducting nature and the lightfastness of these pigments. Poor optical absorption and minority carrier mobility are the main properties responsible for the observed stability. In addition, novel fundamental insights into the role played by Na atoms in the stabilization of the otherwise intrinsically unstable Pb2Sb2O7 pyrochlore were obtained.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000526394000016 Publication Date 2020-04-14
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0897-4756 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 8.6 Times cited 8 Open Access OpenAccess
Notes Universiteit Antwerpen; Belgian Federal Science Policy Office; Approved Most recent IF: 8.6; 2020 IF: 9.466
Call Number EMAT @ emat @c:irua:168819 Serial 6363
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Author Yasui, Y.; Lahabi, K.; Fernández Becerra, V.; Fermin, R.; Anwar, M.S.; Yonezawa, S.; Terashima, T.; Milošević, M.V.; Aarts, J.; Maeno, Y.
Title Spontaneous emergence of Josephson junctions in homogeneous rings of single-crystal Sr₂RuO₄ Type A1 Journal article
Year (down) 2020 Publication npj Quantum Materials Abbreviated Journal
Volume 5 Issue 1 Pages 21-28
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The chiral p-wave order parameter in Sr2RuO4 would make it a special case amongst the unconventional superconductors. A consequence of this symmetry is the possible existence of superconducting domains of opposite chirality. At the boundary of such domains, the locally suppressed condensate can produce an intrinsic Josephson junction. Here, we provide evidence of such junctions using mesoscopic rings, structured from Sr2RuO4 single crystals. Our order parameter simulations predict such rings to host stable domain walls across their arms. This is verified with transport experiments on loops, with a sharp transition at 1.5 K, which show distinct critical current oscillations with periodicity corresponding to the flux quantum. In contrast, loops with broadened transitions at around 3 K are void of such junctions and show standard Little-Parks oscillations. Our analysis demonstrates the junctions are of intrinsic origin and makes a compelling case for the existence of superconducting domains.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000525721000001 Publication Date 2020-04-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2397-4648 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 10 Open Access
Notes ; The authors would like to thank S. Goswami, A. Singh, M. Kupryianov, S. Bakurskiy, J. Jobst, T. Nakamura, K. Adachi, Y. Liu, and Y. Asano for valuable discussions and comments, and F. Hubler, Y. Nakamura, and Y. Yamaoka for their technical contribution. This work was supported by a Grant-in-Aid for Scientific Research on Innovative Areas “Topological Materials Science” (KAKENHI Grant Nos. JP15H05852, JP15K21717, JP15H05851), JSPS-EPSRC Core-to-Core program (A. Advanced Research Network), JSPS research fellow (KAKENHI Grant No. JP16J10404), Grant-in-Aid JSPS KAKENHI JP26287078 and JP17H04848, and the Netherlands Organisation for Scientific Research (NWO/OCW), as part of the Frontiers of Nanoscience program. V.F.B. acknowledges support from the Foundation for Polish Science through the IRA Programme co-financed by EU within SG OP. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:168553 Serial 6613
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Author Li, L.L.; Bacaksiz, C.; Nakhaee, M.; Pentcheva, R.; Peeters, F.M.; Yagmurcukardes, M.
Title Single-layer Janus black arsenic-phosphorus (b-AsP): optical dichroism, anisotropic vibrational, thermal, and elastic properties Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 13 Pages 134102-134109
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract By using density functional theory (DFT) calculations, we predict a puckered, dynamically stable Janus single-layer black arsenic-phosphorus (b-AsP), which is composed of two different atomic sublayers, arsenic and phosphorus atoms. The calculated phonon spectrum reveals that Janus single-layer b-AsP is dynamically stable with either pure or coupled optical phonon branches arising from As and P atoms. The calculated Raman spectrum indicates that due to the relatively strong P-P bonds, As atoms have no contribution to the highfrequency optical vibrations. In addition, the orientation-dependent isovolume heat capacity reveals anisotropic contributions of LA and TA phonon branches to the low-temperature thermal properties. Unlike pristine single layers of b-As and b-P, Janus single-layer b-AsP exhibits additional out-of-plane asymmetry which leads to important consequences for its electronic, optical, and elastic properties. In contrast to single-layer b-As, Janus single-layer b-AsP is found to possess a direct band gap dominated by the P atoms. Moreover, real and imaginary parts of the dynamical dielectric function, including excitonic effects, reveal the highly anisotropic optical feature of the Janus single-layer. A tight-binding (TB) model is also presented for Janus single-layer b-AsP, and it is shown that, with up to seven nearest hoppings, the TB model reproduces well the DFT band structure in the low-energy region around the band gap. This TB model can be used in combination with the Green's function approach to study, e.g., quantum transport in finite systems based on Janus single-layer b-AsP. Furthermore, the linear-elastic properties of Janus single-layer b-AsP are investigated, and the orientation-dependent in-plane stiffness and Poisson ratio are calculated. It is found that the Janus single layer exhibits strong in-plane anisotropy in its Poisson ratio much larger than that of single-layer b-P. This Janus single layer is relevant for promising applications in optical dichroism and anisotropic nanoelasticity.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000524531900001 Publication Date 2020-04-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 30 Open Access
Notes ; This work was supported by the German Science Foundation (DFG) within SFB/TRR80 (project G3) and the FLAGERA project TRANS-2D-TMD. M.Y. was supported by a postdoctoral fellowship from the Flemish Science Foundation (FWO-Vl). Computational resources were provided by the Flemish Supercomputer Center (VSC) and Leibniz Supercomputer Centrum (project pr87ro). ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:168554 Serial 6602
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Author Bafekry, A.; Stampfl, C.; Ghergherehchi, M.
Title Strain, electric-field and functionalization induced widely tunable electronic properties in MoS2/BC3, /C3N and / C3N4 van der Waals heterostructures Type A1 Journal article
Year (down) 2020 Publication Nanotechnology (Bristol. Print) Abbreviated Journal
Volume Issue Pages 295202 pp
Keywords A1 Journal article; Engineering sciences. Technology; Condensed Matter Theory (CMT)
Abstract In this paper, the effect of BC3, C3N and C3N4BC(3) and MoS2/C(3)N4 heterostructures are direct semiconductors with band gaps of 0.4 and 1.74 eV, respectively, while MoS2/C3N is a metal. Furthermore, the influence of strain and electric field on the electronic structure of these van der Waals heterostructures is investigated. The MoS2/BC3 heterostructure, for strains larger than -4%, transforms it into a metal where the metallic character is maintained for strains larger than -6%. The band gap decreases with increasing strain to 0.35 eV (at +2%), while for strain (>+6%) a direct-indirect band gap transition is predicted to occur. For the MoS2/C3N heterostructure, the metallic character persists for all strains considered. On applying an electric field, the electronic properties of MoS2/C3N4 are modified and its band gap decreases as the electric field increases. Interestingly, the band gap reaches 30 meV at +0.8 V/angstrom, and with increase above +0.8 V/angstrom, a semiconductor-to-metal transition occurs. Furthermore, we investigated effects of semi- and full-hydrogenation of MoS2/C3N and we found that it leads to a metallic and semiconducting character, respectively.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000532366000001 Publication Date 2020-04-09
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN 0957-4484 Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor Times cited 19 Open Access
Notes ; This work has supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government(MSIT)(NRF-2017R1A2B2011989). ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:169523 Serial 6444
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Author Kahraman, Z.; Yagmurcukardes, M.; Sahin, H.
Title Functionalization of single-layer TaS₂ and formation of ultrathin Janus structures Type A1 Journal article
Year (down) 2020 Publication Journal Of Materials Research Abbreviated Journal J Mater Res
Volume 35 Issue 11 Pages 1397-1406
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Ab initio calculations are performed to investigate the structural, vibrational, electronic, and piezoelectric properties of functionalized single layers of TaS2. We find that single-layer TaS2 is a suitable host material for functionalization via fluorination and hydrogenation. The one-side fluorinated (FTaS2) and hydrogenated (HTaS2) single layers display indirect gap semiconducting behavior in contrast to bare metallic TaS2. On the other hand, it is shown that as both surfaces of TaS2 are saturated anti-symmetrically, the formed Janus structure is a dynamically stable metallic single layer. In addition, it is revealed that out-of-plane piezoelectricity is created in all anti-symmetric structures. Furthermore, the Janus-type single-layer has the highest specific heat capacity to which longitudinal and transverse acoustical phonon modes have contribution at low temperatures. Our findings indicate that single-layer TaS2 is suitable for functionalization via H and F atoms that the formed, anti-symmetric structures display distinctive electronic, vibrational, and piezoelectric properties.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000540764300005 Publication Date 2020-04-08
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0884-2914 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 2.7 Times cited 1 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 TUBITAK under the project number 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 post-doctoral fellowship (M.Y.). ; Approved Most recent IF: 2.7; 2020 IF: 1.673
Call Number UA @ admin @ c:irua:170185 Serial 6525
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Author Bafekry, A.; Yagmurcukardes, M.; Akgenc, B.; Ghergherehchi, M.; Nguyen, C.
Title Van der Waals heterostructures of MoS₂ and Janus MoSSe monolayers on graphitic boron-carbon-nitride (BC₃, C₃N, C₃N₄ and C₄N₃) nanosheets: a first-principles study Type A1 Journal article
Year (down) 2020 Publication Journal Of Physics D-Applied Physics Abbreviated Journal J Phys D Appl Phys
Volume Issue Pages 1-10
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract In this work, we extensively investigate the structural and electronic properties of van der Waals heterostructures (HTs) constructed by MoS${2}$/$BC3$, MoS${2}$/$C3N$, MoS${2}$/$C3N4$, MoS${2}$/$C4N3$ and those using Janus MoSSe instead of MoS$2$ by performing density functional theory calculations. The electronic band structure calculations and the corresponding partial density of states reveal that the significant changes are driven by quite strong layer-layer interaction between the constitutive layers. Our results show that although all monolayers are semiconductors as free-standing layers, the MoS${2}$/$C3N$ and MoS${2}$/$C4N3$ bilayer HTs display metallic behavior as a consequence of transfer of charge carriers between two constituent layers. In addition, it is found that in MoSSe/$C3N$ bilayer HT, the degree of metallicity is affected by the interface chalcogen atom type when Se atoms are facing to $C3N$ layer, the overlap of the bands around the Fermi level is smaller. Moreover, the half-metallic magnetic $C4N3$ is shown to form magnetic half-metallic trilayer HT with MoS$2$ independent of the stacking sequence, i.e. whether it is sandwiched or two $C4N3$ layer encapsulate MoS$2$ layer. We further analyze the trilayer HTs in which MoS$2$ is encapsulated by two different monolayers and it is revealed that at least with one magnetic monolayer, it is possible to construct a magnetic trilayer. While the trilayer of $C4N3$/MoS${2}$/$BC3$ and $C4N3$/MoS${2}$/$C3N4$ exhibit half-metallic characteristics, $C4N3$/MoS${_2}$/$C3$N possesses a magnetic metallic ground state. Overall, our results reveal that holly structures of BCN crystals are suitable for heterostructure formation even over van der Waals type interaction which significantly changes electronic nature of the constituent layers.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000543344800001 Publication Date 2020-04-07
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0022-3727 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.4 Times cited Open Access
Notes Approved Most recent IF: 3.4; 2020 IF: 2.588
Call Number UA @ admin @ c:irua:169754 Serial 6651
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Author Saberi-Pouya, S.; Conti, S.; Perali, A.; Croxall, A.F.; Hamilton, A.R.; Peeters, F.M.; Neilson, D.
Title Experimental conditions for the observation of electron-hole superfluidity in GaAs heterostructures Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 14 Pages 140501-140506
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract The experimental parameter ranges needed to generate superfluidity in optical and drag experiments in GaAs double quantum wells are determined using a formalism that includes self-consistent screening of the Coulomb pairing interaction in the presence of the superfluid. The very different electron and hole masses in GaAs make this a particularly interesting system for superfluidity with exotic superfluid phases predicted in the BCS-Bose-Einstein condensation crossover regime. We find that the density and temperature ranges for superfluidity cover the range for which optical experiments have observed indications of superfluidity but that existing drag experiments lie outside the superfluid range. We also show that, for samples with low mobility with no macroscopically connected superfluidity, if the superfluidity survives in randomly distributed localized pockets, standard quantum capacitance measurements could detect these pockets.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000523627600001 Publication Date 2020-04-06
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 3.7 Times cited 13 Open Access
Notes ; We thank K. Das Gupta, F. Dubin, U. Siciliani de Cumis, M. Pini, and J. Waldie for illuminating discus-sions. This work was partially supported by the Flemish Science Foundation (FWO-Vl) and the Australian Government through the Australian Research Council Centre of Excellence in Future Low-Energy Electronics (Project No. CE170100039). ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:168561 Serial 6517
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Author Bafekry, A.; Neek-Amal, M.; Peeters, F.M.
Title Two-dimensional graphitic carbon nitrides: strain-tunable ferromagnetic ordering Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 16 Pages 165407-165408
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Using first-principle calculations, we systematically study strain tuning of the electronic properties of two- dimensional graphitic carbon nitride nanosheets with empirical formula CnNm. We found the following: (i) the ferromagnetic ordered state in the metal-free systems (n, m) = (4,3), (10,9), and (14,12) remains stable in the presence of strain of about 6%. However, the system (9,7) loses its ferromagnetic ordering when increasing strain. This is due to the presence of topological defects in the (9,7) system, which eliminates the asymmetry between spin up and spin down of the p(z) orbitals when strain is applied. (ii) By applying uniaxial strain, a band gap opens in systems which are initially gapless. (iii) In semiconducting systems which have an initial gap of about 1 eV, the band gap is closed with applying uniaxial strain.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000523630200012 Publication Date 2020-04-06
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 3.7 Times cited 22 Open Access
Notes ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:168560 Serial 6643
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Author Vargas Paredes, A.A.; Shanenko, A.A.; Vagov, A.; Milošević, M.V.; Perali, A.
Title Crossband versus intraband pairing in superconductors: signatures and consequences of the interplay Type A1 Journal article
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 9 Pages 094516-94517
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract We analyze the paradigmatic competition between intraband and crossband Cooper-pair formation in twoband superconductors, neglected in most works to date. We derive the phase-sensitive gap equations and describe the crossover between the intraband-dominated and the crossband-dominated regimes, delimited by a “gapless” state. Experimental signatures of crosspairing comprise notable gap splitting in the excitation spectrum, non-BCS behavior of gaps versus temperature, as well as changes in the pairing symmetry as a function of temperature. The consequences of these findings are illustrated on the examples of MgB2 and Ba0.6K0.4Fe2As2.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000522074900002 Publication Date 2020-03-27
Series Editor Series Title Abbreviated Series Title
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ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
Impact Factor 3.7 Times cited 14 Open Access
Notes ; This collaborative work was fostered within the international Multi Super network on Multi-condensate Superconductivity and Superfluidity [70]. The authors thank Andrea Guidini for his help during the initial stage of this work and Laura Fanfarillo for useful discussions. This work was partially supported by the Italian MIUR through the PRIN 2015 program (Contract No. 2015C5SEJJ001) and the Research Foundation -Flanders (FWO). A.A.V.-P. acknowledges support by the joint doctoral program and by the Erasmus+ exchange between the University of Antwerp and the University of Camerino. M.V.M. gratefully acknowledges support from a Visiting Professorship at the University of Camerino. A.S. and A.V. acknowledge support from the CAPES/Print Grant, Process No. 88887.333666/ 2019-00 (Brazil) and the Russian Science Foundation Project No. 18-12-00429, respectively. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:168605 Serial 6479
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Author Conti, S.; Neilson, D.; Peeters, F.M.; Perali, A.
Title Transition metal dichalcogenides as strategy for high temperature electron-hole superfluidity Type A1 Journal article
Year (down) 2020 Publication Condensed Matter Abbreviated Journal
Volume 5 Issue 1 Pages 22-12
Keywords A1 Journal article; Condensed Matter Theory (CMT)
Abstract Condensation of spatially indirect excitons, with the electrons and holes confined in two separate layers, has recently been observed in two different double layer heterostructures. High transition temperatures were reported in a double Transition Metal Dichalcogenide (TMD) monolayer system. We briefly review electron-hole double layer systems that have been proposed as candidates for this interesting phenomenon. We investigate the double TMD system WSe2/hBN/MoSe2, using a mean-field approach that includes multiband effects due to the spin-orbit coupling and self-consistent screening of the electron-hole Coulomb interaction. We demonstrate that the transition temperature observed in the double TMD monolayers, which is remarkably high relative to the other systems, is the result of (i) the large electron and hole effective masses in TMDs, (ii) the large TMD band gaps, and (iii) the presence of multiple superfluid condensates in the TMD system. The net effect is that the superfluidity is strong across a wide range of densities, which leads to high transition temperatures that extend as high as TBKT=150 K.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000523711200017 Publication Date 2020-03-23
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 7 Open Access
Notes ; This work was partially supported by the Fonds Wetenschappelijk Onderzoek (FWO-Vl), the Methusalem Foundation and the FLAG-ERA project TRANS-2D-TMD. ; Approved Most recent IF: NA
Call Number UA @ admin @ c:irua:168658 Serial 6636
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Author Van der Donck, M.; Zarenia, M.; Peeters, F.M.
Title Reply to “Comment on `Excitons, trions, and biexcitons in transition-metal dichalcogenides: Magnetic-field dependence'” Type Editorial
Year (down) 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
Volume 101 Issue 12 Pages 127402
Keywords Editorial; Condensed Matter Theory (CMT)
Abstract In the Comment, the authors state that the separation of the relative and center of mass variables in our work is not correct. Here we point out that there is a typographical error, i.e., qi instead of -e, in two of our equations which, when corrected, makes the Comment redundant. Within the ansatzes mentioned in our paper all our results are correct, in contrast to the claims of the Comment.
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Corporate Author Thesis
Publisher Place of Publication Editor
Language Wos 000519990800011 Publication Date 2020-03-18
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
Impact Factor 3.7 Times cited Open Access
Notes ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
Call Number UA @ admin @ c:irua:167680 Serial 6594
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