toggle visibility
Search within Results:
Display Options:

Select All    Deselect All
 |   | 
Details
   print
  Records
Author Wang, J.; Andelkovic, M.; Wang, G.; Peeters, F.M.
  Title Molecular collapse in graphene: Sublattice symmetry effect Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 102 Issue 6 Pages 064108-8
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Atomic collapse can be observed in graphene because of its large “effective” fine structure constant, which enables this phenomenon to occur for an impurity charge as low as Z(c) similar to 1-2. Here we investigate the effect of the sublattice symmetry on molecular collapse in two spatially separated charge tunable vacancies, which are located on the same (A-A type) or different (A-B type) sublattices. We find that the broken sublattice symmetry: (1) does not affect the location of the main bonding and antibonding molecular collapse peaks, (2) but shifts the position of the satellite peaks, because they are a consequence of the breaking of the local sublattice symmetry, and (3) there are vacancy characteristic collapse peaks that only occur for A-B type vacancies, which can be employed to distinguish them experimentally from the A-A type. As the charge, energy, and separation distance increase, the additional collapse features merge with the main molecular collapse peaks. We show that the spatial distribution around the vacancy site of the collapse states allows us to differentiate the molecular from the frustrated collapse.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000562320700002 Publication Date 2020-08-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 3 Open Access
  Notes ; This work was supported by the National Natural Science Foundation of China (Grants No. 61874038 and No. 61704040), National Key R&D Program Grant 2018YFE0120000, the scholarship from China Scholarship Council (CSC: 201908330548), and TRANS2DTMD FlagEra project. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:172065 Serial 6562
Permanent link to this record
 

 
Author Plumadore, R.; Baskurt, M.; Boddison-Chouinard, J.; Lopinski, G.; Modarresi, M.; Potasz, P.; Hawrylak, P.; Sahin, H.; Peeters, F.M.; Luican-Mayer, A.
  Title Prevalence of oxygen defects in an in-plane anisotropic transition metal dichalcogenide Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 102 Issue 20 Pages 205408
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Atomic scale defects in semiconductors enable their technological applications and realization of different quantum states. Using scanning tunneling microscopy and spectroscopy complemented by ab initio calculations we determine the nature of defects in the anisotropic van der Waals layered semiconductor ReS2. We demonstrate the in-plane anisotropy of the lattice by directly visualizing chains of rhenium atoms forming diamond-shaped clusters. Using scanning tunneling spectroscopy we measure the semiconducting gap in the density of states. We reveal the presence of lattice defects and by comparison of their topographic and spectroscopic signatures with ab initio calculations we determine their origin as oxygen atoms absorbed at lattice point defect sites. These results provide an atomic-scale view into the semiconducting transition metal dichalcogenides, paving the way toward understanding and engineering their properties.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000587595800007 Publication Date 2020-11-09
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 9 Open Access
  Notes ; The authors acknowledge funding from National Sciences and Engineering Research Council (NSERC) Discovery Grant No. RGPIN-2016-06717. We also acknowledge the support of the Natural Sciences and Engineering Research Council of Canada (NSERC) through QC2DM Strategic Project No. STPGP 521420. P.H. thanks uOttawa Research Chair in Quantum Theory of Materials for support. P.P. acknowledges partial financial support from National Science Center (NCN), Poland, Grant Maestro No. 2014/14/A/ST3/00654, and calculations were performed in theWroclaw Center for Networking and Supercomputing. H.S. acknowledges financial support from TUBITAK under Project No. 117F095 and from Turkish Academy of Sciences under the GEBIP program. Our computational resources were provided by TUBITAK ULAKBIM, High Performance and Grid Computing Center (TR-Grid eInfrastructure). ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:173525 Serial 6584
Permanent link to this record
 

 
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 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.
  Address
  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 (up) 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
Permanent link to this record
 

 
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 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 (up) 3.7 Times cited 39 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
Permanent link to this record
 

 
Author Zhang, L.; Zhang, Y.-Y.; Zha, G.-Q.; Milošević, M.V.; Zhou, S.-P.
  Title Skyrmionic chains and lattices in s plus id superconductors Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 101 Issue 6 Pages 064501
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We report characteristic vortex configurations in s + id superconductors with time-reversal symmetry breaking, exposed to magnetic field. A vortex in the s + id state tends to have an opposite phase winding between s- and d-wave condensates. We find that this peculiar feature together with the competition between s- and d-wave symmetry results in three distinct classes of vortical configurations. When either s or d condensate absolutely dominates, vortices form a conventional lattice. However, when one condensate is relatively dominant, vortices organize in chains that exhibit skyrmionic character, separating the chiral components of the s +/- id order parameter into domains within and outside the chain. Such skyrmionic chains are found stable even at high magnetic field. When s and d condensates have comparable strength, vortices split cores in two chiral components to form full-fledged skyrmions, i.e., coreless topological structures with an integer topological charge, organized in a lattice. We provide characteristic magnetic field distributions of all states, enabling their identification in, e.g., scanning Hall probe and scanning SQUID experiments. These unique vortex states are relevant for high-T-c cuprate and iron-based superconductors, where the relative strength of competing pairing symmetries is expected to be tuned by temperature and/or doping level, and can help distinguish s + is and s + id superconducting phases.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000510745600005 Publication Date 2020-02-03
  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 (up) 3.7 Times cited 7 Open Access
  Notes ; The authors acknowledge useful discussions with Yong-Ping Zhang. This research was supported by the National Natural Science Foundation of China under Grants No. 61571277 and No. 61771298. L.-F.Z. and M.V.M. acknowledge support from Research Foundation-Flanders (FWO-Vlaanderen). ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:166507 Serial 6605
Permanent link to this record
 

 
Author Menezes, R.M.; de Souza Silva, C.C.; Milošević, M.V.
  Title Spin textures in chiral magnetic monolayers with suppressed nearest-neighbor exchange Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 101 Issue 21 Pages 214429-9
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract High tunability of two-dimensional magnetic materials (by strain, gating, heterostructuring, or otherwise) provides unique conditions for studying versatile magnetic properties and controlling emergent magnetic phases. Expanding the scope of achievable magnetic phenomena in such materials is important for both fundamental and technological advances. Here we perform atomistic spin-dynamics simulations to explore the (chiral) magnetic phases of atomic monolayers in the limit of suppressed first-neighbors exchange interaction. We report the rich phase diagram of exotic magnetic configurations, obtained for both square and honeycomb lattice symmetries, comprising coexistence of ferromagnetic and antiferromagnetic spin cycloids, as well as multiple types of magnetic skyrmions. We perform a minimum-energy path analysis for the skyrmion collapse to evaluate the stability of such topological objects and reveal that magnetic monolayers could be good candidates to host the antiferromagnetic skyrmions that are experimentally evasive to date.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000540910100002 Publication Date 2020-06-18
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 1 Open Access
  Notes ; This work was supported by the Research Foundation-Flanders (FWO-Vlaanderen) and Brazilian Agencies FACEPE (under Grant No. APQ-0198-1.05/14), CAPES, and CNPq. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:170176 Serial 6610
Permanent link to this record
 

 
Author Yagmurcukardes, M.; Peeters, F.M.
  Title Stable single layer of Janus MoSO: strong out-of-plane piezoelectricity Type A1 Journal article
  Year 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 (up) 3.7 Times cited 66 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
Permanent link to this record
 

 
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 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.
  Address
  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 (up) 3.7 Times cited 8 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
Permanent link to this record
 

 
Author Van der Donck, M.; Conti, S.; Perali, A.; Hamilton, A.R.; Partoens, B.; Peeters, F.M.; Neilson, D.
  Title Three-dimensional electron-hole superfluidity in a superlattice close to room temperature Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 102 Issue 6 Pages 060503
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Although there is strong theoretical and experimental evidence for electron-hole superfluidity in separated sheets of electrons and holes at low T, extending superfluidity to high T is limited by strong two-dimensional fluctuations and Kosterlitz-Thouless effects. We show this limitation can be overcome using a superlattice of alternating electron- and hole-doped semiconductor monolayers. The superfluid transition in a three-dimensional superlattice is not topological, and for strong electron-hole pair coupling, the transition temperature T-c can be at room temperature. As a quantitative illustration, we show T-c can reach 270 K for a superfluid in a realistic superlattice of transition metal dichalcogenide monolayers.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000562320700001 Publication Date 2020-08-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 8 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., by the FLAG-ERA project TRANS-2D-TMD, and by the Australian Government through the Australian Research Council Centre of Excellence in Future Low-Energy Electronics (Project No. CE170100039). We thank Milorad V. Milossevi ' c, Pierbiagio Pieri, and Jacques Tempere for helpful discussions. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:172064 Serial 6628
Permanent link to this record
 

 
Author Leishman, A.W.D.; Menezes, R.M.; Longbons, G.; Bauer, E.D.; Janoschek, M.; Honecker, D.; DeBeer-Schmitt, L.; White, J.S.; Sokolova, A.; Milošević, M.V.; Eskildsen, M.R.
  Title Topological energy barrier for skyrmion lattice formation in MnSi Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 102 Issue 10 Pages 104416-104419
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We report the direct measurement of the topological skyrmion energy barrier through a hysteresis of the skyrmion lattice in the chiral magnet MnSi. Measurements were made using small-angle neutron scattering with a custom-built resistive coil to allow for high-precision minor hysteresis loops. The experimental data were analyzed using an adapted Preisach model to quantify the energy barrier for skyrmion formation and corroborated by the minimum-energy path analysis based on atomistic spin simulations. We reveal that the skyrmion lattice in MnSi forms from the conical phase progressively in small domains, each of which consisting of hundreds of skyrmions, and with an activation barrier of several eV.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000568994800005 Publication Date 2020-09-14
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 1 Open Access
  Notes ; This work was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Award No. DE-SC0005051 (A.W.D.L., G.L., M.R.E.), the Research Foundation -Flanders (FWO-Vlaanderen) (R.M.M., M.V.M.), and Brazilian Agencies FACEPE, CAPES and CNPq (R.M.M.). M.J. was supported by the LANL Directed Research and Development (LDRD) program via the Directed Research (DR) project “A New Approach to Mesoscale Functionality: Emergent Tunable Superlattices (20150082DR).” E.D.B. was supported by the U.S. Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering, under project “Quantum Fluctuations in Narrow-Band Systems.” A portion of this research used resources at the High Flux Isotope Reactor, a DOE Office of Science User Facility operated by the Oak Ridge National Laboratory. Part of this work is based on experiments performed at the Swiss spallation neutron source SINQ, Paul Scherrer Institute, Villigen, Switzerland. We acknowledge useful conversations with E. Louden, D. Green, and A. Francisco in preparation for these experiments, as well as the assistance of K. Avers, G. Taufer, M. Harrington, M. Bartkowiak, and C. Baldwin in completing them. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:171959 Serial 6631
Permanent link to this record
 

 
Author Bafekry, A.; Neek-Amal, M.
  Title Tuning the electronic properties of graphene-graphitic carbon nitride heterostructures and heterojunctions by using an electric field Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 101 Issue 8 Pages 085417-10
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Integration of graphene-based two-dimensional materials is essential for nanoelectronics applications. Using density-functional theory, we systematically investigate the electronic properties of vertically stacked graphene-graphitic carbon nitrides (GE/GCN). We also studied the covalently lateral stitched graphene-graphitic carbon nitrides (GE-GCN heterojunctions). The effects of perpendicular electric field on the electronic properties of six different heterostructures, i.e., (i) one layer of GE on top of a layer of CnNm with (n, m) = (3,1), (3,4), and (4,3) and (ii) three heterostructures CnNm/Cn'Nm', where (n, m) not equal (n', m') are elucidated. The most important calculated features are (i) the systems GE/C3N4, C3N/C3N4, GE-C3N, GE-C4N3, and C3N-C3N4 exhibit semiconducting characteristics having small band gaps of Delta(0)=20, 250, 100, 100, 80 meV, respectively while (ii) the systems GE/C4N3, C3N/C4N3, and C3N-C4N3 show ferromagnetic-metallic properties. In particular, we found that, in semiconducting heterostructures, the band gap increases nontrivially with increasing the absolute value of the applied perpendicular electric field. This work is useful for designing heterojunctions and heterostructures made of graphene and other two-dimensional materials such as those proposed in recent experiments [X. Liu and M. C. Hersam Sci. Adv. 5, 6444 (2019)].
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000515659700007 Publication Date 2020-02-26
  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 (up) 3.7 Times cited 24 Open Access
  Notes ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:167760 Serial 6640
Permanent link to this record
 

 
Author Bafekry, A.; Neek-Amal, M.; Peeters, F.M.
  Title Two-dimensional graphitic carbon nitrides: strain-tunable ferromagnetic ordering Type A1 Journal article
  Year 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 (up) 3.7 Times cited 27 Open Access
  Notes ; ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:168560 Serial 6643
Permanent link to this record
 

 
Author Savchenko, T.M.; Buzzi, M.; Howald, L.; Ruta, S.; Vijayakumar, J.; Timm, M.; Bracher, D.; Saha, S.; Derlet, P.M.; Béché, A.; Verbeeck, J.; Chantrell, R.W.; Vaz, C.A.F.; Nolting, F.; Kleibert, A.
  Title Single femtosecond laser pulse excitation of individual cobalt nanoparticles Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 102 Issue 20 Pages 205418
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT)
  Abstract Laser-induced manipulation of magnetism at the nanoscale is a rapidly growing research topic with potential for applications in spintronics. In this work, we address the role of the scattering cross section, thermal effects, and laser fluence on the magnetic, structural, and chemical stability of individual magnetic nanoparticles excited by single femtosecond laser pulses. We find that the energy transfer from the fs laser pulse to the nanoparticles is limited by the Rayleigh scattering cross section, which in combination with the light absorption of the supporting substrate and protective layers determines the increase in the nanoparticle temperature. We investigate individual Co nanoparticles (8 to 20 nm in size) as a prototypical model system, using x-ray photoemission electron microscopy and scanning electron microscopy upon excitation with single femtosecond laser pulses of varying intensity and polarization. In agreement with calculations, we find no deterministic or stochastic reversal of the magnetization in the nanoparticles up to intensities where ultrafast demagnetization or all-optical switching is typically reported in thin films. Instead, at higher fluences, the laser pulse excitation leads to photo-chemical reactions of the nanoparticles with the protective layer, which results in an irreversible change in the magnetic properties. Based on our findings, we discuss the conditions required for achieving laser-induced switching in isolated nanomagnets.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000589602000005 Publication Date 2020-11-16
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9950 ISBN Additional Links UA library record; WoS full record
  Impact Factor (up) 3.7 Times cited 1 Open Access OpenAccess
  Notes This work received funding by the Swiss National Foundation (SNF) (Grants No. 200021160186 and No. 2002153540), the Swiss Nanoscience Institute (SNI) (Grant No. SNI P1502), the European Union’s Horizon 2020 research and innovation programme under Grant Agreement No. 737093 (FEMTOTERABYTE), and the COST Action CA17123 (MAGNETOFON). Part of this work was performed at the SIM beamline of the Swiss Light Source (SLS), Paul Scherrer Institut, Villigen, Switzerland. Part of the simulations were undertaken on the VIKING cluster, which is a high-performance compute facility provided by the University of York. We kindly acknowledge Anja Weber from PSI for preparation of substrates with marker structures. A.B. and Jo Verbeeck acknowledge funding through FWO Project No. G093417N (“Compressed sensing enabling low dose imaging in transmission electron microscopy”) from the Flanders Research Fund. Jo Verbeeck acknowledges funding from the European Union’s Horizon 2020 research and innovation program under Grant Agreement No. 823717 – ESTEEM3. S.S. acknowledges ETH Zurich Post-Doctoral fellowship and Marie Curie actions for people COFUND program.; esteem3JRA; esteem3reported Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number EMAT @ emat @c:irua:174273 Serial 6669
Permanent link to this record
 

 
Author Milovanović, S.P.; Andelkovic, M.; Covaci, L.; Peeters, F.M.
  Title Band flattening in buckled monolayer graphene Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 102 Issue 24 Pages 245427
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)
  Abstract The strain fields of periodically buckled graphene induce a periodic pseudomagnetic field (PMF) that modifies the electronic band structure. From the geometry, amplitude, and period of the periodic pseudomagnetic field, we determine the necessary conditions to access the regime of correlated phases by examining the band flattening. As compared to twisted bilayer graphene the proposed system has the advantages that (1) only a single layer of graphene is needed, (2) one is not limited to hexagonal superlattices, and (3) narrower flat bandwidth and larger separation between flat bands can be induced. We, therefore, propose that periodically strained graphene single layers can become a platform for the exploration of exotic many-body phases.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000602844600007 Publication Date 2020-12-28
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 27 Open Access OpenAccess
  Notes ; S.P.M. is supported by the Flemish Science Foundation (FWO). We thank E. Y. Andrei, Y. Jiang, and J. Mao for fruitful discussions. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:175021 Serial 6684
Permanent link to this record
 

 
Author Shekarforoush, S.; Jalali, H.; Yagmurcukardes, M.; Milošević, M.V.; Neek-Amal, M.
  Title Optoelectronic properties of confined water in angstrom-scale slits Type A1 Journal article
  Year 2020 Publication Physical Review B Abbreviated Journal Phys Rev B
  Volume 102 Issue 23 Pages 235406
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The optoelectronic properties of confined water form one of the most active research areas in the past few years. Here we present the multiscale methodology to discern the out-of-plane electronic and dipolar dielectric constants (epsilon(el)(perpendicular to) and epsilon(diP)(perpendicular to)) of strongly confined water. We reveal that epsilon(perpendicular to el) and epsilon(diP)(perpendicular to) become comparable for water confined in angstrom-scale channels (with a height of less than 15 angstrom) within graphene (GE) and hexagonal boron nitride (hBN) bilayers. Channel height (h) associated with a minimum in both epsilon(e)(l)(perpendicular to) and epsilon(dip)(perpendicular to) is linked to the formation of the ordered structure of ice for h approximate to (7 -7.5) angstrom. The recently measured total dielectric constant epsilon(T)(perpendicular to) of nanoconfined water [L. Fumagalli et al., Science 360, 1339 (2018)] is corroborated by our results. Furthermore, we evaluate the contribution from the encapsulating membranes to the dielectric properties, as a function of the interlayer spacing, i.e., the height of the confining channel for water. Finally, we conduct analysis of the optical properties of both confined water and GE membranes, and show that the electron energy loss function of confined water strongly differs from that of bulk water.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000595856100004 Publication Date 2020-12-04
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 1 Open Access
  Notes ; This work was supported by the Research Foundation – Flanders (FWO). M.Y. gratefully acknowledges his FWO postdoctoral mandate. ; Approved Most recent IF: 3.7; 2020 IF: 3.836
  Call Number UA @ admin @ c:irua:175051 Serial 6695
Permanent link to this record
 

 
Author Wang, J.; Van Pottelberge, R.; Zhao, W.-S.; Peeters, F.M.
  Title Coulomb impurity on a Dice lattice : atomic collapse and bound states Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 105 Issue 3 Pages 035427
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The modification of the quantum states in a Dice lattice due to a Coulomb impurity are investigated. The energy-band structure of a pristine Dice lattice consists of a Dirac cone and a flat band at the Dirac point. We use the tight-binding formalism and find that the flat band states transform into a set of discrete bound states whose electron density is localized on a ring around the impurity mainly on two of the three sublattices. Its energy is proportional to the strength of the Coulomb impurity. Beyond a critical strength of the Coulomb potential atomic collapse states appear that have some similarity with those found in graphene with the difference that the flat band states contribute with an additional ringlike electron density that is spatially decoupled from the atomic collapse part. At large value of the strength of the Coulomb impurity the flat band bound states anticross with the atomic collapse states.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000749375200002 Publication Date 2022-01-28
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 3 Open Access Not_Open_Access
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:186387 Serial 6977
Permanent link to this record
 

 
Author Yu, Y.; Chen, X.; Liu, X.; Li, J.; Sanyal, B.; Kong, X.; Peeters, F.M.; Li, L.
  Title Ferromagnetism with in-plane magnetization, Dirac spin-gapless semiconducting properties, and tunable topological states in two-dimensional rare-earth metal dinitrides Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 105 Issue 2 Pages 024407
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Since the successful synthesis of bulk single crystals MoN2 and ReN2, which have a layered structure, transition-metal dinitrides have attracted considerable attention in recent years. Here, we focus on rare-earth metal (Rem) elements, and propose seven stable Rem dinitride monolayers with a 1T structure, namely, 1T-RemN2. We use first-principles calculations, and find that these monolayers have a ferromagnetic ground state with in-plane magnetization. Without spin-orbit coupling (SOC), the band structures are spin-polarized with Dirac points at the Fermi level. Remarkably, the 1T-LuN2 monolayer exhibits an isotropic magnetocrystalline anisotropy energy in the xy plane with in-plane magnetization, indicating easy tunability of the magnetization direction. When rotating the magnetization vector in the xy plane, we propose a model that accurately describes the variation of the SOC band gap and the two possible topological states (Weyl-like semimetal and Chern insulator states) whose properties are tunable. The Weyl-like semimetal state is a critical point between the two Chern insulator states with opposite sign of the Chern numbers (+/- 1). The nontrivial band gap (up to 60.3 meV) and the Weyl-like semimetal state are promising for applications in spintronic devices.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000742384700001 Publication Date 2022-01-06
  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 (up) 3.7 Times cited 13 Open Access Not_Open_Access: Available from 06.07.2202
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:186514 Serial 6991
Permanent link to this record
 

 
Author Wambacq, E.; Alloul, A.; Grunert, O.; Carrette, J.; Vermeir, P.; Spanoghe, J.; Sakarika, M.; Vlaeminck, S.E.; Haesaert, G.
  Title Aerobes and phototrophs as microbial organic fertilizers : exploring mineralization, fertilization and plant protection features Type A1 Journal article
  Year 2022 Publication PLoS ONE Abbreviated Journal Plos One
  Volume 17 Issue 2 Pages e0262497-15
  Keywords A1 Journal article; Engineering sciences. Technology; Sustainable Energy, Air and Water Technology (DuEL)
  Abstract Organic fertilizers and especially microbial biomass, also known as microbial fertilizer, can enable a paradigm shift to the conventional fertilizer-to-food chain, particularly when produced on secondary resources. Microbial fertilizers are already common practice (e.g. Bloom® and Synagro); yet microbial fertilizer blends to align the nutrient release profile to the plant’s needs are, thus far, unexplored. Moreover, most research only focuses on direct fertilization effects without considering added value properties, such as disease prevention. This study has explored three promising types of microbial fertilizers, namely dried biomass from a consortium of aerobic heterotrophic bacteria, a microalga (Arthrospira platensis) and a purple non-sulfur bacterium (Rhodobacter sphaeroides). Mineralization and nitrification experiments showed that the nitrogen mineralization profile can be tuned to the plant’s needs by blending microbial fertilizers, without having toxic ammonium peaks. In a pot trial with perennial ryegrass (Lolium perenne L.), the performance of microbial fertilizers was similar to the reference organic fertilizer, with cumulative dry matter yields of 5.6–6.7 g per pot. This was confirmed in a pot trial with tomato (Solanum lycopersicum L.), showing an average total plant length of 90–99 cm after a growing period of 62 days for the reference organic fertilizer and the microbial fertilizers. Moreover, tomato plants artificially infected with powdery mildew (Oidium neolycopersici), a devastating disease for the horticultural industry, showed reduced disease symptoms when A. platensis was present in the growing medium. These findings strengthen the application potential of this novel class of organic fertilizers in the bioeconomy, with a promising match between nutrient mineralization and plant requirements as well as added value in crop protection.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000775890100025 Publication Date 2022-02-02
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-6203 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:185568 Serial 7122
Permanent link to this record
 

 
Author Zhang, H.Y.; Xiao, Y.M.; N. Li, Q.; Ding, L.; Van Duppen, B.; Xu, W.; Peeters, F.M.
  Title Anisotropic and tunable optical conductivity of a two-dimensional semi-Dirac system in the presence of elliptically polarized radiation Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 105 Issue 11 Pages 115423-115429
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We investigate the effect of ellipticity ratio of the polarized radiation field on optoelectronic properties of a two-dimensional (2D) semi-Dirac (SD) system. The optical conductivity is calculated within the energy balance equation approach derived from the semiclassical Boltzmann equation. We find that there exists the anisotropic optical absorption induced via both the intra-and interband electronic transition channels in the perpendicular xx and yy directions. Furthermore, we examine the effects of the ellipticity ratio, the temperature, the carrier density, and the band-gap parameter on the optical conductivity of the 2D SD system placed in transverse and vertical directions, respectively. It is shown that the ellipticity ratio, temperature, carrier density, and band-gap parameter can play the important roles in tuning the strength, peak position, and shape of the optical conductivity spectrum. The results obtained from this study indicate that the 2D SD system can be a promising anisotropic and tunable optical and optoelectronic material for applications in innovative 2D optical and optoelectronic devices, which are active in the infrared and terahertz bandwidths.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000802810700002 Publication Date 2022-03-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 3 Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:188660 Serial 7125
Permanent link to this record
 

 
Author Shafiei, M.; Fazileh, F.; Peeters, F.M.; Milošević, M.V.
  Title Controlling the hybridization gap and transport in a thin-film topological insulator : effect of strain, and electric and magnetic field Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 106 Issue 3 Pages 035119-7
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract In a thin-film topological insulator (TI), the edge states on two surfaces may couple by quantum tunneling, opening a gap known as the hybridization gap. Controlling the hybridization gap and transport has a variety of potential uses in photodetection and energy-harvesting applications. In this paper, we report the effect of strain, and electric and magnetic field, on the hybridization gap and transport in a thin Bi2Se3 film, investigated within the tight-binding theoretical framework. We demonstrate that vertical compression decreases the hybridization gap, as does tensile in-plane strain. Applying an electric field breaks the inversion symmetry and leads to a Rashba-like spin splitting proportional to the electric field, hence closing and reopening the gap. The influence of a magnetic field on thin-film TI is also discussed, starting from the role of an out-of-plane magnetic field on quantum Hall states. We further demonstrate that the hybridization gap can be controlled by an in-plane magnetic field, and that by applying a sufficiently strong field a quantum phase transition from an insulator to a semimetal can be achieved.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000832277500001 Publication Date 2022-07-13
  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 (up) 3.7 Times cited 7 Open Access Not_Open_Access
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:189515 Serial 7140
Permanent link to this record
 

 
Author Mirzakhani, M.; da Costa, D.R.; Peeters, F.M.
  Title Isolated and hybrid bilayer graphene quantum rings Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 105 Issue 11 Pages 115430-11
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Using the continuum model, we investigate the electronic properties of two types of bilayer graphene (BLG) quantum ring (QR) geometries: (i) An isolated BLG QR and (ii) a monolayer graphene (MLG) with a QR put on top of an infinite graphene sheet (hybrid BLG QR). Solving the Dirac-Weyl equation in the presence of a perpendicular magnetic field and applying the infinite mass boundary condition at the ring boundaries, we obtain analytical results for the energy levels and corresponding wave spinors for both structures. In the case of isolated BLG QR, we observe a sizable and magnetically tunable band gap which agrees with the tight-binding transport simulations. Our analytical results also show the intervalley symmetry EeK (m) = ???EK??? h (m) between the electron (e) and the hole (h) states (m is the angular momentum quantum number) for the energy spectrum of the isolated BLG QR. The presence of interface boundary in a hybrid BLG QR modifies drastically the energy levels as compared with that of an isolated BLG QR. Its energy levels are tunable from MLG dot to isolated BLG QR and to MLG Landau energy levels as the magnetic field is varied. Our predictions can be verified experimentally using different techniques such as by magnetotransport measurements.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000801209300006 Publication Date 2022-03-28
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 4 Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:188703 Serial 7175
Permanent link to this record
 

 
Author Moura, V.N.; Dantas, D.S.; Farias, G.A.; Chaves, A.; Milošević, M.V.
  Title Latent superconductivity at parallel interfaces in a superlattice dominated by another collective quantum phase Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 106 Issue 1 Pages 014516-10
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We theoretically examine behavior of superconductivity at parallel interfaces separating the domains of another dominant collective excitation, such as charge density waves or spin density waves. Due to their competitive coupling in a two-component Ginzburg-Landau model, suppression of the dominant order parameter at the interfacial planes allows for nucleation of the (hidden) superconducting order parameter at those planes. In such a case, we demonstrate how the number of the parallel interfacial planes and the distance between them are linked to the number and the size of the emerging superconducting gaps in the system, as well as the versatility and temperature evolution of the possible superconducting phases. These findings bear relevance to a broad selection of known layered superconducting materials, as well as to further design of artificial (e.g., oxide) superlattices, where the interplay between competing order parameters paves the way towards otherwise unattainable superconducting states, some with enhanced superconducting critical temperature.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000834346000004 Publication Date 2022-07-22
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record
  Impact Factor (up) 3.7 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:189520 Serial 7179
Permanent link to this record
 

 
Author Vizarim, N.P.; Souza, J.C.B.; Reichhardt, C.J.O.; Reichhardt, C.; Milošević, M.V.; Venegas, P.A.
  Title Soliton motion in skyrmion chains : stabilization and guidance by nanoengineered pinning Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 105 Issue 22 Pages 224409-224412
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract Using a particle-based model we examine the depinning motion of solitons in skyrmion chains in quasi -onedimensional (1D) and two-dimensional (2D) systems containing embedded 1D interfaces. The solitons take the form of a particle or hole in a commensurate chain of skyrmions. Under an applied drive, just above a critical depinning threshold, the soliton moves with a skyrmion Hall angle of zero. For higher drives, the entire chain depins, and in a 2D system we observe that both the solitons and chain move at zero skyrmion Hall angle and then transition to a finite skyrmion Hall angle as the drive increases. In a 2D system with a 1D interface that is at an angle to the driving direction, there can be a reversal of the sign of the skyrmion Hall angle from positive to negative. Our results suggest that solitons in skyrmion systems could be used as information carriers in racetrack geometries that would avoid the drawbacks of finite skyrmion Hall angles. The soliton states become mobile at significantly lower drives than the depinning transition of the skyrmion chains themselves.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000823038900004 Publication Date 2022-06-16
  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 (up) 3.7 Times cited 2 Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:189671 Serial 7209
Permanent link to this record
 

 
Author Cunha, S.M.; da Costa, D.R.; Pereira, J.M., Jr.; Costa Filho, R.N.; Van Duppen, B.; Peeters, F.M.
  Title Tunneling properties in α-T₃ lattices : effects of symmetry-breaking terms Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 105 Issue 16 Pages 165402-165414
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract The alpha-T3 lattice model interpolates a honeycomb (graphene-like) lattice and a T3 (also known as dice) lattice via the parameter alpha. These lattices are made up of three atoms per unit cell. This gives rise to an additional dispersionless flat band touching the conduction and valence bands. Electrons in this model are analogous to Dirac fermions with an enlarged pseudospin, which provides unusual tunneling features like omnidirectional Klein tunneling, also called super-Klein tunneling (SKT). However, it is unknown how small deviations in the equivalence between the atomic sites, i.e., variations in the alpha parameter, and the number of tunnel barriers changes the transmission properties. Moreover, it is interesting to learn how tunneling occurs through regions where the energy spectrum changes from linear with a middle flat band to a hyperbolic dispersion. In this paper we investigate these properties, its dependence on the number of square barriers and the alpha parameter for either gapped and gapless cases. Furthermore, we compare these results to the case where electrons tunnel from a region with linear dispersion to a region with a bandgap. In the latter case, contrary to tunneling through a potential barrier, the SKT is no longer observed. Finally, we find specific cases where transmission is allowed due to a symmetry breaking of sublattice equivalence.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000805195200001 Publication Date 2022-04-01
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 2469-9969; 2469-9950 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:188614 Serial 7222
Permanent link to this record
 

 
Author Lazarevic, N.; Baum, A.; Milosavljevic, A.; Peis, L.; Stumberger, R.; Bekaert, J.; Solajic, A.; Pesic, J.; Wang, A.; Scepanovic, M.; Abeykoon, A.M.M.; Milošević, M.V.; Petrovic, C.; Popovic, Z.V.; Hackl, R.
  Title Evolution of lattice, spin, and charge properties across the phase diagram of Fe1-xSx Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 106 Issue 9 Pages 094510-94519
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract A Raman scattering study covering the entire substitution range of the FeSe1-xSx solid solution is presented. Data were taken as a function of sulfur concentration x for 0 <= x <= 1, of temperature and of scattering symmetry. All types of excitations including phonons, spins, and charges are analyzed in detail. It is observed that the energy and width of the iron-related B-1g phonon mode vary continuously across the entire range of sulfur substitution. The A(1g) chalcogenide mode disappears above x = 0.23 and reappears at a much higher energy for x = 0.69. In a similar way the spectral features appearing at finite doping in A(1g) symmetry vary discontinuously. The magnetic excitation centered at approximately 500 cm(-1) disappears above x = 0.23 where the A(1g) lattice excitations exhibit a discontinuous change in energy. The low-energy mode associated with fluctuations displays maximal intensity at the nematostructural transition and thus tracks the phase boundary.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000917933500004 Publication Date 2022-09-19
  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
  Impact Factor (up) 3.7 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:194397 Serial 7304
Permanent link to this record
 

 
Author dela Encarnacion, C.; Lenzi, E.; Henriksen-Lacey, M.; Molina, B.; Jenkinson, K.; Herrero, A.; Colas, L.; Ramos-Cabrer, P.; Toro-Mendoza, J.; Orue, I.; Langer, J.; Bals, S.; Jimenez de Aberasturi, D.; Liz-Marzan, L.M.
  Title Hybrid magnetic-plasmonic nanoparticle probes for multimodal bioimaging Type A1 Journal article
  Year 2022 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal J Phys Chem C
  Volume 126 Issue 45 Pages 19519-19531
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Multimodal contrast agents, which take advantage of different imaging modalities, have emerged as an interesting approach to overcome the technical limitations of individual techniques. We developed hybrid nanoparticles comprising an iron oxide core and an outer gold spiky layer, stabilized by a biocompatible polymeric shell. The combined magnetic and optical properties of the different components provide the required functionalities for magnetic resonance imaging (MRI), surface-enhanced Raman scattering (SERS), and fluorescence imaging. The fabrication of such hybrid nanoprobes comprised the adsorption of small gold nanoparticles onto premade iron oxide cores, followed by controlled growth of spiky gold shells. The gold layer thickness and branching degree (tip sharpness) can be controlled by modifying both the density of Au nanoparticle seeds on the iron oxide cores and the subsequent nanostar growth conditions. We additionally demonstrated the performance of these hybrid multifunctional nanoparticles as multimodal contrast agents for correlative imaging of in vitro cell models and ex vivo tissues.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000883021700001 Publication Date 2022-11-04
  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 (up) 3.7 Times cited 10 Open Access Not_Open_Access
  Notes The authors acknowledge financial support from the European Research Council (ERC-AdG-2017, 787510) and MCIN/AEI/10.13039/501100011033 through grants PID2019-108854RA-I00 and Maria de Maeztu Unit of Excellence No. MDM-2017-0720. S.B. and K.J. acknowledge financial support from the European Commission under the Horizon 2020Programme by Grant No. 823717 (ESTEEM3) and ERC Consolidator Grant No. 815128 (REALNANO) . Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:192104 Serial 7311
Permanent link to this record
 

 
Author Nulens, L.; Dausy, H.; Wyszynski, M.J.; Raes, B.; Van Bael, M.J.; Milošević, M.V.; Van de Vondel, J.
  Title Metastable states and hidden phase slips in nanobridge SQUIDs Type A1 Journal article
  Year 2022 Publication Physical review B Abbreviated Journal Phys Rev B
  Volume 106 Issue 13 Pages 134518-134519
  Keywords A1 Journal article; Condensed Matter Theory (CMT)
  Abstract We fabricated an asymmetric nanoscale SQUID consisting of one nanobridge weak link and one Dayem bridge weak link. The current phase relation of these particular weak links is characterized by multivaluedness and linearity. While the latter is responsible for a particular magnetic field dependence of the critical current (so-called vorticity diamonds), the former enables the possibility of different vorticity states (phase winding numbers) existing at one magnetic field value. In experiments the observed critical current value is stochastic in nature, does not necessarily coincide with the current associated with the lowest energy state and critically depends on the measurement conditions. In this paper, we unravel the origin of the observed metastability as a result of the phase dynamics happening during the freezing process and while sweeping the current. Moreover, we employ special measurement protocols to prepare the desired vorticity state and identify the (hidden) phase slip dynamics ruling the detected state of these nanodevices. In order to gain insights into the dynamics of the condensate and, more specifically the hidden phase slips, we performed time-dependent Ginzburg-Landau simulations.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000904657300007 Publication Date 2022-10-31
  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 (up) 3.7 Times cited 1 Open Access OpenAccess
  Notes Approved Most recent IF: 3.7
  Call Number UA @ admin @ c:irua:193393 Serial 7321
Permanent link to this record
 

 
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 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.
  Address
  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 (up) 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
Permanent link to this record
 

 
Author Tchakoua, T.; Powell, A.D.; Gerrits, N.; Somers, M.F.; Doblhoff-Dier, K.; Busnengo, H.F.; Kroes, G.-J.
  Title Simulating highly activated sticking of H₂ on Al(110) : quantum versus quasi-classical dynamics Type A1 Journal article
  Year 2023 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal
  Volume 127 Issue 11 Pages 5395-5407
  Keywords A1 Journal article; Engineering sciences. Technology; Plasma Lab for Applications in Sustainability and Medicine – Antwerp (PLASMANT)
  Abstract We evaluate the importance of quantum effects on the sticking of H2 on Al(110) for conditions that are close to those of molecular beam experiments that have been done on this system. Calculations with the quasi-classical trajectory (QCT) method and with quantum dynamics (QD) are performed using a model in which only motion in the six molecular degrees of freedom is allowed. The potential energy surface used has a minimum barrier height close to the value recently obtained with the quantum Monte Carlo method. Monte Carlo averaging over the initial rovibrational states allowed the QD calculations to be done with an order of magnitude smaller computational expense. The sticking probability curve computed with QD is shifted to lower energies relative to the QCT curve by 0.21 to 0.05 kcal/mol, with the highest shift obtained for the lowest incidence energy. Quantum effects are therefore expected to play a small role in calculations that would evaluate the accuracy of electronic structure methods for determining the minimum barrier height to dissociative chemisorption for H2 + Al(110) on the basis of the standard procedure for comparing results of theory with molecular beam experiments.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000971346700001 Publication Date 2023-03-14
  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 (up) 3.7 Times cited Open Access OpenAccess
  Notes Approved Most recent IF: 3.7; 2023 IF: 4.536
  Call Number UA @ admin @ c:irua:196071 Serial 8525
Permanent link to this record
 

 
Author Kavak, S.; Kadu, A.A.; Claes, N.; Sánchez-Iglesias, A.; Liz-Marzán, L.M.; Batenburg, K.J.; Bals, S.
  Title Quantitative 3D Investigation of Nanoparticle Assemblies by Volumetric Segmentation of Electron Tomography Data Sets Type A1 Journal article
  Year 2023 Publication The journal of physical chemistry: C : nanomaterials and interfaces Abbreviated Journal
  Volume 127 Issue 20 Pages 9725-9734
  Keywords A1 Journal article; Engineering sciences. Technology; Electron microscopy for materials research (EMAT)
  Abstract Morphological characterization of nanoparticle assemblies and hybrid nanomaterials is critical in determining their structure-property relationships as well as in the development of structures with desired properties. Electron tomography has become a widely utilized technique for the three-dimensional characterization of nanoparticle assemblies. However, the extraction of quantitative morphological parameters from the reconstructed volume can be a complex and labor-intensive task. In this study, we aim to overcome this challenge by automating the volumetric segmentation process applied to three-dimensional reconstructions of nanoparticle assemblies. The key to enabling automated characterization is to assess the performance of different volumetric segmentation methods in accurately extracting predefined quantitative descriptors for morphological characterization. In our methodology, we compare the quantitative descriptors obtained through manual segmentation with those obtained through automated segmentation methods, to evaluate their accuracy and effectiveness. To show generality, our study focuses on the characterization of assemblies of CdSe/CdS quantum dots, gold nanospheres and CdSe/CdS encapsulated in polymeric micelles, and silica-coated gold nanorods decorated with both CdSe/CdS or PbS quantum dots. We use two unsupervised segmentation algorithms: the watershed transform and the spherical Hough transform. Our results demonstrate that the choice of automated segmentation method is crucial for accurately extracting the predefined quantitative descriptors. Specifically, the spherical Hough transform exhibits superior performance in accurately extracting quantitative descriptors, such as particle size and interparticle distance, thereby allowing for an objective, efficient, and reliable volumetric segmentation of complex nanoparticle assemblies.
  Address
  Corporate Author Thesis
  Publisher Place of Publication Editor
  Language Wos 000991752700001 Publication Date 2023-05-25
  Series Editor Series Title Abbreviated Series Title
  Series Volume Series Issue Edition
  ISSN 1932-7447 ISBN Additional Links UA library record; WoS full record; WoS citing articles
  Impact Factor (up) 3.7 Times cited 2 Open Access OpenAccess
  Notes Fonds Wetenschappelijk Onderzoek, 1181122N ; Horizon 2020 Framework Programme, 861950 ; H2020 European Research Council, 815128 ; Approved Most recent IF: 3.7; 2023 IF: 4.536
  Call Number EMAT @ emat @c:irua:196971 Serial 8793
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: