95375 20210902121833.0 doi 10.1103/PhysRevLett.124.257401 sideral 119181 ART-2020-119181 eng Brey, L. Nonlocal Quantum Effects in Plasmons of Graphene Superlattices 2020 Access copy available to the general public Unrestricted By using a nonlocal, quantum mechanical response function we study graphene plasmons in a one-dimensional superlattice (SL) potential V0cosG0x. The SL introduces a quantum energy scale EG~vFG0 associated with electronic subband transitions. At energies lower than EG, the plasmon dispersion is highly anisotropic; plasmons propagate perpendicularly to the SL axis, but become damped by electronic transitions along the SL direction. These results question the validity of semiclassical approximations for describing low energy plasmons in periodic structures. At higher energies, the dispersion becomes isotropic and Drude-like with effective Drude weights related to the average of the absolute value of the local chemical potential. Full quantum mechanical treatment of the kinetic energy thus introduces nonlocal effects that delocalize the plasmons in the SL, making the system behave as a metamaterial even near singular points where the charge density vanishes. info:eu-repo/grantAgreement/ES/DGA/Q-MAD info:eu-repo/grantAgreement/ES/MINECO/FIS2017-82260-P info:eu-repo/grantAgreement/ES/MINECO/MAT2017-88358-C3-1-R info:eu-repo/grantAgreement/ES/MINECO/MDM-2014-0377 info:eu-repo/grantAgreement/ES/MINECO/PGC2018-096955-B-C42 info:eu-repo/grantAgreement/ES/MINECO/PGC2018-097018-B-I00 info:eu-repo/semantics/openAccess All rights reserved http://www.europeana.eu/rights/rr-f/ 9.161 2020 PHYSICS, MULTIDISCIPLINARY 7 / 85 = 0.082 2020 Q1 T1 3.688 2020 Physics and Astronomy (miscellaneous) 2020 Q1 info:eu-repo/semantics/article info:eu-repo/semantics/publishedVersion Stauber, T. Martín-Moreno, L. Universidad de Zaragoza (orcid)0000-0001-9273-8165 Gómez-Santos, G. 2003 395 Universidad de Zaragoza Dpto. Física Materia Condensa. Área Física Materia Condensada 124, 25 (2020), 257401 [6 pp.] Phys. rev. lett. Physical Review Letters 0031-9007 926551 http://zaguan.unizar.es/record/95375/files/texto_completo.pdf Versión publicada 21409 http://zaguan.unizar.es/record/95375/files/texto_completo.jpg?subformat=icon icon Versión publicada oai:zaguan.unizar.es:95375 articulos driver 2021-09-02-10:17:53 ARTICLE