TY - JOUR
T1 - Chiral anomaly trapped in Weyl metals
T2 - Nonequilibrium valley polarization at zero magnetic field
AU - Perez-Piskunow, Pablo M.
AU - Bovenzi, Nicandro
AU - Akhmerov, Anton R.
AU - Breitkreiz, Maxim
PY - 2021
Y1 - 2021
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=85114775357&partnerID=8YFLogxK
U2 - 10.21468/SCIPOSTPHYS.11.2.046
DO - 10.21468/SCIPOSTPHYS.11.2.046
M3 - Article
AN - SCOPUS:85114775357
SN - 2542-4653
VL - 11
JO - SciPost Physics
JF - SciPost Physics
IS - 2
M1 - 046
ER -