High field magneto-transmission investigation of natural graphite

TL;DR

This study uses high magnetic fields to investigate Landau level transitions in natural graphite, confirming the effectiveness of a simplified SWM model and clarifying the nature of transition splitting.

Contribution

It demonstrates that a two-parameter SWM model accurately describes Landau level transitions in natural graphite at high magnetic fields.

Findings

Two series of H-point transitions with √B dependence observed.

A simplified SWM model with two parameters fits all data.

High-field splitting not due to Dirac cone asymmetry.

Abstract

Magneto-transmission measurements in magnetic fields in the range B=20-60T have been performed to probe the H and K-point Landau level transitions in natural graphite. At the H-point, two series of transitions, whose energy evolves as $\sqrt{B}$ are observed. A reduced Slonczewski, Weiss and McClure (SWM) model with only two parameters to describe the intra-layer (gamma0) and inter-layer (gamma1) coupling correctly describes all observed transitions. Polarization resolved measurements confirm that the observed apparent splitting of the H-point transitions at high magnetic field cannot be attributed to an asymmetry of the Dirac cone.