Report on 2104.10059v1

Abstract

In Weyl semimetals the application of parallel electric and magnetic fields leads to valley polarization-an occupation disbalance of valleys of opposite chirality-a direct consequence of the chiral anomaly.In this work, we present numerical tools to explore such nonequilibrium effects in spatially confined three-dimensional systems with a variable disorder potential, giving exact solutions to leading order in the disorder potential and the applied electric field.Application to a Weyl-metal slab shows that valley polarization also occurs without an external magnetic field as an effect of chiral anomaly "trapping": Spatial confinement produces chiral bulk states, which enable the valley polarization in a similar way as the chiral states induced by a magnetic field.Despite its finite-size origin, the valley polarization can persist up to macroscopic length scales if the disorder potential is sufficiently long ranged, so that direct inter-valley scattering is suppressed and the relaxation then goes via the Fermi-arc surface states.

Authors 4

1. Pablo M. Perez-Piskunow

   Consejo Superior de Investigaciones Científicas · Institut Català de Nanociència i Nanotecnologia · Barcelona Institute of Science and Technology

   Affiliation as printed

   Catalan Institute of Nanoscience and Nanotechnology (ICN2) ,

   CSIC and BIST, Campus UAB, Bellaterra, 08193 Barcelona, Spain

   Catalan Institute of Nanoscience and Nanotechnology (ICN2),

2. Nicandro Bovenzi Aachen Instituut-Lorentz

   Leiden University

   Affiliation as printed

   Instituut-Lorentz , Universiteit Leiden , P.O. Box 9506 , 2300 RA Leiden , The Netherlands

   Instituut-Lorentz, Universiteit Leiden, P.O. Box 9506, 2300 RA Leiden, The Netherlands

3. Anton Roustiamovich Akhmerov

   Consejo Superior de Investigaciones Científicas · Barcelona Institute of Science and Technology · Delft University of Technology

   Affiliation as printed

   CSIC and BIST , Campus UAB , Bellaterra , 08193 Barcelona , Spain

   Kavli Institute of Nanoscience , Delft University of Technology , P.O. Box 4056 , 2600 GA Delft , The Netherlands

   Kavli Institute of Nanoscience, Delft University of Technology, P.O. Box 4056, 2600 GA Delft, The Netherlands

4. Maxim Breitkreiz

   Freie Universität Berlin

   Affiliation as printed

   Dahlem Center for Complex Quantum Systems and Fachbereich Physik , Freie Universität Berlin , 14195 Berlin , Germany

   Dahlem Center for Complex Quantum Systems and Fachbereich Physik, Freie Universität Berlin, 14195 Berlin, Germany