Intrinsic optical dichroism in the chiral superconducting state of Sr$_{2}$RuO$_{4}$

TL;DR

This paper investigates the intrinsic optical dichroism in chiral superconductors, proposing a mechanism that explains the Kerr effect in Sr$_{2}$RuO$_{4}$ and predicts temperature-dependent coherence effects in Hall conductivity.

Contribution

It introduces a new intrinsic mechanism for optical dichroism in chiral superconductors with inter-band order parameters, explaining experimental Kerr effects.

Findings

Non-zero dichroic signal in systems with inter-band order parameters

Prediction of coherence factor effects in temperature dependence of Hall conductivity

Potential explanation for Kerr effect observed in Sr$_{2}$RuO$_{4}$

Abstract

We present an analysis of the Hall conductivity $\sigma_{xy}(\omega, T)$ in time reversal symmetry breaking states of exotic superconductors. We find that the dichroic signal is non-zero in systems with inter-band order parameters. This new intrinsic mechanism may explain the Kerr effect observed in strontium ruthenate and possibly other superconductors. We predict coherence factor effects in the temperature dependence of the imaginary part of the ac Hall conductivity $ Im\sigma_{xy}(\omega, T)$, which can be tested experimentally.