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Author Lavor, I.R.; Chaves, A.; Peeters, F.M.; Van Duppen, B. pdf  url
doi  openurl
  Title Tunable coupling of terahertz Dirac plasmons and phonons in transition metal dichalcogenide-based van der Waals heterostructures Type A1 Journal article
  Year (down) 2021 Publication 2d Materials Abbreviated Journal 2D Mater  
  Volume Issue Pages 015018  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Dirac plasmons in graphene hybridize with phonons of transition metal dichalcogenides (TMDs) when the materials are combined in so-called van der Waals heterostructures (vdWh), thus forming surface plasmon-phonon polaritons (SPPPs). The extend to which these modes are coupled depends on the TMD composition and structure, but also on the plasmons' properties. By performing realistic simulations that account for the contribution of each layer of the vdWh separately, we calculate how the strength of plasmon-phonon coupling depends on the number and composition of TMD layers, on the graphene Fermi energy and the specific phonon mode. From this, we present a semiclassical theory that is capable of capturing all relevant characteristics of the SPPPs. We find that it is possible to realize both strong and ultra-strong coupling regimes by tuning graphene's Fermi energy and changing TMD layer number.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000722020100001 Publication Date 2021-11-08  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record  
  Impact Factor 6.937 Times cited Open Access OpenAccess  
  Notes Approved Most recent IF: 6.937  
  Call Number UA @ admin @ c:irua:183053 Serial 7036  
Permanent link to this record
 

 
Author Lavor, I.R.; da Costa, D.R.; Covaci, L.; Milošević, M.V.; Peeters, F.M.; Chaves, A. url  doi
openurl 
  Title Zitterbewegung of moiré excitons in twisted MoS₂/WSe₂ heterobilayers Type A1 Journal article
  Year (down) 2021 Publication Physical review letters Abbreviated Journal  
  Volume 127 Issue 10 Pages 106801  
  Keywords A1 Journal article; Electron microscopy for materials research (EMAT); Condensed Matter Theory (CMT)  
  Abstract The moire pattern observed in stacked noncommensurate crystal lattices, such as heterobilayers of transition metal dichalcogenides, produces a periodic modulation of their band gap. Excitons subjected to this potential landscape exhibit a band structure that gives rise to a quasiparticle dubbed the moire exciton. In the case of MoS2/WSe2 heterobilayers, the moire trapping potential has honeycomb symmetry and, consequently, the moire exciton band structure is the same as that of a Dirac-Weyl fermion, whose mass can be further tuned down to zero with a perpendicularly applied field. Here we show that, analogously to other Dirac-like particles, the moire exciton exhibits a trembling motion, also known as Zitterbewegung, whose long timescales are compatible with current experimental techniques for exciton dynamics. This promotes the study of the dynamics of moire excitons in van der Waals heterostructures as an advantageous solid-state platform to probe Zitterbewegung, broadly tunable by gating and interlayer twist angle.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000692200800020 Publication Date 2021-08-31  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1079-7114 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor Times cited 4 Open Access OpenAccess  
  Notes Approved Most recent IF: NA  
  Call Number UA @ admin @ c:irua:181599 Serial 6896  
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Author Lavor, I.R.; da Costa, D.R.; Chaves, A.; Sena, S.H.R.; Farias, G.A.; Van Duppen, B.; Peeters, F.M. pdf  url
doi  openurl
  Title Effect of zitterbewegung on the propagation of wave packets in ABC-stacked multilayer graphene : an analytical and computational approach Type A1 Journal article
  Year (down) 2021 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat  
  Volume 33 Issue 9 Pages 095503  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The time evolution of a low-energy two-dimensional Gaussian wave packet in ABC-stacked n-layer graphene (ABC-NLG) is investigated. Expectation values of the position (x, y) of center-of-mass and the total probability densities of the wave packet are calculated analytically using the Green's function method. These results are confirmed using an alternative numerical method based on the split-operator technique within the Dirac approach for ABC-NLG, which additionally allows to include external fields and potentials. The main features of the zitterbewegung (trembling motion) of wave packets in graphene are demonstrated and are found to depend not only on the wave packet width and initial pseudospin polarization, but also on the number of layers. Moreover, the analytical and numerical methods proposed here allow to investigate wave packet dynamics in graphene systems with an arbitrary number of layers and arbitrary potential landscapes.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000599465000001 Publication Date 2020-11-25  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.649 Times cited 3 Open Access OpenAccess  
  Notes ; Discussions with D J P de Sousa and J M Pereira Jr are gratefully acknowledged. This work was financially supported by the Brazilian Council for Research (CNPq), under the PQ and PRONEX/FUNCAP programs, and by CAPES. One of us (BVD) is supported by the FWO-Vl. DRC is supported by CNPq Grant Nos. 310019/2018-4 and 437067/2018-1. ; Approved Most recent IF: 2.649  
  Call Number UA @ admin @ c:irua:174953 Serial 6687  
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Author Lavor, I.R.; Cavalcante, L.S.R.; Chaves, A.; Peeters, F.M.; Van Duppen, B. url  doi
openurl 
  Title Probing the structure and composition of van der Waals heterostructures using the nonlocality of Dirac plasmons in the terahertz regime Type A1 Journal article
  Year (down) 2021 Publication 2d Materials Abbreviated Journal 2D Mater  
  Volume 8 Issue 1 Pages 015014  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract Dirac plasmons in graphene are very sensitive to the dielectric properties of the environment. We show that this can be used to probe the structure and composition of van der Waals heterostructures (vdWh) put underneath a single graphene layer. In order to do so, we assess vdWh composed of hexagonal boron nitride and different types of transition metal dichalcogenides (TMDs). By performing realistic simulations that account for the contribution of each layer of the vdWh separately and including the importance of the substrate phonons, we show that one can achieve single-layer resolution by investigating the nonlocal nature of the Dirac plasmon-polaritons. The composition of the vdWh stack can be inferred from the plasmon-phonon coupling once it is composed by more than two TMD layers. Furthermore, we show that the bulk character of TMD stacks for plasmonic screening properties in the terahertz regime is reached only beyond 100 layers.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000582820500001 Publication Date 2020-10-06  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2053-1583 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 6.937 Times cited 2 Open Access OpenAccess  
  Notes ; This work was financially supported by the Brazilian Council for Research (CNPq), Brazilian National Council for the Improvement of Higher Education (CAPES) and by the Research Foundation Flanders (FWO) through a postdoctoral fellowship to B.V.D. ; Approved Most recent IF: 6.937  
  Call Number UA @ admin @ c:irua:173507 Serial 6696  
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Author Lavor, I.R.; da Costa, D.R.; Chaves, A.; Farias, G.A.; Macedo, R.; Peeters, F.M. pdf  url
doi  openurl
  Title Magnetic field induced vortices in graphene quantum dots Type A1 Journal article
  Year (down) 2020 Publication Journal Of Physics-Condensed Matter Abbreviated Journal J Phys-Condens Mat  
  Volume 32 Issue 15 Pages 155501  
  Keywords A1 Journal article; Condensed Matter Theory (CMT)  
  Abstract The energy spectrum and local current patterns in graphene quantum dots (QD) are investigated for different geometries in the presence of an external perpendicular magnetic field. Our results demonstrate that, for specific geometries and edge configurations, the QD exhibits vortex and anti-vortex patterns in the local current density, in close analogy to the vortex patterns observed in the probability density current of semiconductor QD, as well as in the order parameter of mesoscopic superconductors.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Wos 000520149200001 Publication Date 2019-12-20  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-8984 ISBN Additional Links UA library record; WoS full record; WoS citing articles  
  Impact Factor 2.7 Times cited 5 Open Access  
  Notes ; This work was financially supported by the CAPES foundation and CNPq (Science Without Borders, PQ and FUNCAP/PRONEX programs). ; Approved Most recent IF: 2.7; 2020 IF: 2.649  
  Call Number UA @ admin @ c:irua:167670 Serial 6558  
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