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Title: Chiral magnetic effect without chirality source in asymmetric Weyl semimetals

Abstract

Here, we describe a new type of the Chiral Magnetic Effect (CME) that should occur inWeyl semimetals with an asymmetry in the dispersion relations of the left- and right-handed chiral Weyl fermions. In such materials, time-dependent pumping of electrons from a non-chiral external source can generate a non-vanishing chiral chemical potential. This is due to the different capacities of the left- and right-handed (LH and RH) chiral Weyl cones arising from the difference in the density of states in the LH and RH cones. The chiral chemical potential then generates, via the chiral anomaly, a current along the direction of an applied magnetic field even in the absence of an external electric field. The source of chirality imbalance in this new setup is thus due to the band structure of the system and the presence of (non-chiral) electron source, and not due to the parallel electric and magnetic fields. We illustrate the effect by an argument based on the effective field theory, and by the chiral kinetic theory calculation for a rotationally invariant Weyl semimetal with different Fermi velocities in the left and right chiral Weyl cones; we also consider the case of a Weyl semimetal with Weyl nodes atmore » different energies. We argue that this effect is generically present in Weyl semimetals with different dispersion relations for LH and RH chiral Weyl cones, such as SrSi 2 recently predicted as a Weyl semimetal with broken inversion and mirror symmetries, as long as the chiral relaxation time is much longer than the transport scattering time.« less

Authors:
 [1];  [2];  [3]
  1. Stony Brook Univ., Stony Brook, NY (United States); Brookhaven National Lab. (BNL), Upton, NY (United States)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States); Kyoto Univ., Kyoto (Japan)
  3. Univ. of Wurzburg, Wurzburg (Germany)
Publication Date:
Research Org.:
Brookhaven National Lab. (BNL), Upton, NY (United States)
Sponsoring Org.:
USDOE Office of Science (SC), Nuclear Physics (NP) (SC-26)
OSTI Identifier:
1462429
Report Number(s):
BNL-207868-2018-JAAM
Journal ID: ISSN 1434-6028; TRN: US1902171
Grant/Contract Number:  
SC0012704
Resource Type:
Accepted Manuscript
Journal Name:
European Physical Journal. B, Condensed Matter and Complex Systems
Additional Journal Information:
Journal Volume: 91; Journal Issue: 5; Journal ID: ISSN 1434-6028
Publisher:
Springer
Country of Publication:
United States
Language:
English
Subject:
73 NUCLEAR PHYSICS AND RADIATION PHYSICS; Solid State and Materials

Citation Formats

Kharzeev, Dmitri E., Kikuchi, Yuta, and Meyer, Rene. Chiral magnetic effect without chirality source in asymmetric Weyl semimetals. United States: N. p., 2018. Web. doi:10.1140/epjb/e2018-80418-1.
Kharzeev, Dmitri E., Kikuchi, Yuta, & Meyer, Rene. Chiral magnetic effect without chirality source in asymmetric Weyl semimetals. United States. doi:10.1140/epjb/e2018-80418-1.
Kharzeev, Dmitri E., Kikuchi, Yuta, and Meyer, Rene. Thu . "Chiral magnetic effect without chirality source in asymmetric Weyl semimetals". United States. doi:10.1140/epjb/e2018-80418-1. https://www.osti.gov/servlets/purl/1462429.
@article{osti_1462429,
title = {Chiral magnetic effect without chirality source in asymmetric Weyl semimetals},
author = {Kharzeev, Dmitri E. and Kikuchi, Yuta and Meyer, Rene},
abstractNote = {Here, we describe a new type of the Chiral Magnetic Effect (CME) that should occur inWeyl semimetals with an asymmetry in the dispersion relations of the left- and right-handed chiral Weyl fermions. In such materials, time-dependent pumping of electrons from a non-chiral external source can generate a non-vanishing chiral chemical potential. This is due to the different capacities of the left- and right-handed (LH and RH) chiral Weyl cones arising from the difference in the density of states in the LH and RH cones. The chiral chemical potential then generates, via the chiral anomaly, a current along the direction of an applied magnetic field even in the absence of an external electric field. The source of chirality imbalance in this new setup is thus due to the band structure of the system and the presence of (non-chiral) electron source, and not due to the parallel electric and magnetic fields. We illustrate the effect by an argument based on the effective field theory, and by the chiral kinetic theory calculation for a rotationally invariant Weyl semimetal with different Fermi velocities in the left and right chiral Weyl cones; we also consider the case of a Weyl semimetal with Weyl nodes at different energies. We argue that this effect is generically present in Weyl semimetals with different dispersion relations for LH and RH chiral Weyl cones, such as SrSi2 recently predicted as a Weyl semimetal with broken inversion and mirror symmetries, as long as the chiral relaxation time is much longer than the transport scattering time.},
doi = {10.1140/epjb/e2018-80418-1},
journal = {European Physical Journal. B, Condensed Matter and Complex Systems},
number = 5,
volume = 91,
place = {United States},
year = {2018},
month = {5}
}

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