Valley Hall effect and nonlocal resistance in locally gapped graphene
Aktor, Thomas (Technical University of Denmark. Center for Nanostructured Graphene)
Garcia, José H (Institut Català de Nanociència i Nanotecnologia)
Roche, Stephan (Institut Català de Nanociència i Nanotecnologia)
Jauho, Antti-Pekka (Technical University of Denmark. Center for Nanostructured Graphene)
Power, Stephen R. (Trinity College Dublin. School of Physics)

Date:	2021
Abstract:	We report on the emergence of bulk, valley-polarized currents in graphene-based devices, driven by spatially varying regions of broken sublattice symmetry, and revealed by nonlocal resistance (RNL) fingerprints. By using a combination of quantum transport formalisms, giving access to bulk properties as well as multiterminal device responses, the presence of a nonuniform local band gap is shown to give rise to valley-dependent scattering and a finite Fermi-surface contribution to the valley Hall conductivity, related to characteristics of RNL. These features are robust against disorder and provide a plausible interpretation of controversial experiments in graphene/hexagonal boron nitride superlattices. Our findings suggest both an alternative mechanism for the generation of valley Hall effect in graphene and a route towards valley-dependent electron optics, by materials and device engineering.
Grants:	European Commission 881603 Ministerio de Economía y Competitividad SEV-2017-0706
Note:	Altres ajuts: ICN2 is funded by the CERCA Programme/Generalitat de Catalunya.
Rights:	Aquest material està protegit per drets d'autor i/o drets afins. Podeu utilitzar aquest material en funció del que permet la legislació de drets d'autor i drets afins d'aplicació al vostre cas. Per a d'altres usos heu d'obtenir permís del(s) titular(s) de drets.
Language:	Anglès
Document:	Article ; recerca ; Versió sotmesa a revisió
Subject:	Dependent scatterings ; Device engineering ; Device response ; Hall conductivity ; Multi terminals ; Quantum transport ; Sublattice symmetry ; Surface contribution
Published in:	Physical review B, Vol. 103, issue 11 (March 2021) , art. 115406, ISSN 2469-9969

DOI: 10.1103/PhysRevB.103.115406

Preprint 7 p, 5.2 MB

The record appears in these collections:
Research literature > UAB research groups literature > Research Centres and Groups (research output) > Experimental sciences > Catalan Institute of Nanoscience and Nanotechnology (ICN2)
Articles > Research articles
Articles > Published articles