Kerr effect in tilted nodal loop semimetals

TL;DR

This paper studies the optical Kerr effect in tilted nodal loop semimetals, revealing how Kerr signals encode information about tilt, loop radius, and chemical potential, aiding their characterization.

Contribution

It provides a comprehensive calculation of the optical conductivity and Kerr response in tilted nodal loop semimetals, linking optical signals to their electronic structure features.

Findings

Kerr rotation and ellipticity depend on tilt velocity and direction.

Optical signals reveal the radius of the nodal loop.

Chemical potential influences the Kerr response.

Abstract

We investigate the optical activity of tilted nodal loop semimetals. We calculate the full conductivity matrix for a band structure containing a nodal loop with possible tilt in the $x-y$ plane, which allows us to study the Kerr rotation and ellipticity both for a thin film and a bulk material. We find signatures in the Kerr signal that give direct information about the tilt velocity and direction, the radius of the nodal loop and the internal chemical potential of the system. These findings should serve as guide to understanding optical measurements of nodal loop semimetals and as an additional tool to characterize them.