Faraday effect in rippled graphene: Magneto-optics and random gauge fields

TL;DR

This paper investigates how ripples in graphene induce pseudomagnetic fields that, combined with external magnetic fields, significantly influence the Faraday rotation of polarized light passing through graphene, revealing potential for characterizing disorder.

Contribution

It provides a theoretical analysis of the interplay between random pseudomagnetic fields from ripples and external magnetic bias on the Faraday effect in graphene.

Findings

Large Faraday rotation observed due to magnetic bias.

Random ripples induce pseudomagnetic fields affecting optical properties.

Potential to identify gauge disorder through combined measurements.

Abstract

A beam of linearly polarized light transmitted through magnetically biased graphene can have its axis of polarization rotated by several degrees after passing the graphene sheet. This large Faraday effect is due to the action of the magnetic field on graphene's charge carriers. As deformations of the graphene membrane result in pseudomagnetic fields acting on the charge carriers, the effect of random mesoscopic corrugations (ripples) can be described as the exposure of graphene to a random pseudomagnetic field. We aim to clarify the interplay of these typically sample inherent fields with the external magnetic bias field and the resulting effect on the Faraday rotation. In principle, random gauge disorder can be identified from a combination of Faraday angle and optical spectroscopy measurements.