Chiral magnetic effect and Maxwell-Chern-Simons electrodynamics in Weyl semimetals

TL;DR

This paper explores how the chiral magnetic effect in Weyl semimetals alters their electromagnetic properties, revealing unique behaviors like magnetic field-dependent plasma frequency and transparency, with potential technological applications.

Contribution

It provides a classical electrodynamics analysis of CME in Weyl semimetals, highlighting unconventional electromagnetic responses and the role of the chiral magnetic length.

Findings

CME causes frequency-dependent skin depth and plasma frequency changes.

Plasma frequency in Weyl semimetals depends strongly on magnetic field.

Weyl semimetals can appear transparent at optical frequencies.

Abstract

The Weyl semimetal, due to a non-zero energy difference in the pair of Weyl nodes shows chiral magnetic effect(CME). This leads to a flow of dissipationless electric current along an applied magnetic field. Such a chiral magnetic effect in Weyl semimetals has been studied using the laws of classical electrodynamics. It has been shown that the CME in a such a semimetal changes the properties namely, frequency dependent skin depth, capacitive transport, plasma frequency etc. in an unconventional way as compared to the conventional metals. In the low frequency regime, the properties are controlled by a natural length scale due to CME called the chiral magnetic length. Further, unlike the conventional metals, the plasma frequency in this case is shown to be strongly magnetic field-dependent. Since the plasma frequency lies below the optical frequency, the Weyl semimetals will look transparent. Such new and novel observations might help in exploiting these class of materials in potential applications which could completely change the future technology.