Decrypting the cyclotron effect in graphite using Kerr rotation spectroscopy

TL;DR

This study provides a detailed microscopic understanding of the cyclotron effect in graphite through Kerr rotation spectroscopy, revealing significant higher-order harmonics that impact magneto-optical applications.

Contribution

It offers the first unified microscopic model accounting for all magneto-optical spectra in graphite, including higher-order cyclotron harmonics at high magnetic fields.

Findings

Second- and fourth-order harmonics are nearly as strong as the fundamental.

Higher-order harmonics are crucial for magneto-optical and magneto-plasmonic applications.

The model accurately describes spectra across a broad magnetic field range.

Abstract

We measure the far-infrared magneto-optical Kerr rotation and reflectivity spectra in graphite and achieve a highly accurate unified microscopic description of all data in a broad range of magnetic fields by taking rigorously the c-axis band dispersion and the trigonal warping into account. We find that the second- and the forth-order cyclotron harmonics are optically almost as strong as the fundamental resonance even at high fields. They must play, therefore, a major role in magneto-optical and magneto-plasmonic applications based on Bernal stacked graphite and multilayer graphene.