Axion electrodynamics of Weyl superconductors with broken time-reversal symmetry

TL;DR

This paper investigates how axion electrodynamics influences the magnetoelectric response of time-reversal breaking Weyl superconductors, revealing effects on London penetration depth and electromagnetic angular momentum.

Contribution

It extends the axion electrodynamics framework to Weyl superconductors, analyzing their unique electromagnetic responses in the London regime.

Findings

Increase in London penetration depth due to axion effects

Interplay between electric and magnetic fields in vortex and Meissner states

Nonvanishing electromagnetic angular momentum in various geometries

Abstract

The low-energy effective description of Weyl semimetals is defined by the axion electrodynamics, which captures the effects arising due to the presence of nodes of opposite chirality in the electronic structure. Here we explore the magnetoelectric response of time-reversal breaking (TRB) Weyl superconductors in the London regime. The influence of the axion contribution leads to an increase in the London penetration depth$-$a behavior that can be anticipated by first considering the photon spectrum of a TRB Weyl semimetal. Moreover, we find that both the Meissner state and the vortex phase feature an interplay between the electric and magnetic fields. This leads to a nonvanishing electromagnetic angular momentum, which we calculate for a number of geometrical configurations.