Cyclotron motion in the vicinity of a Lifshitz transition in graphite

TL;DR

This study investigates graphite's electronic behavior near a Lifshitz transition using magneto-absorption, revealing complex cyclotron resonance patterns that align better with quasi-classical models than quantum perturbation methods.

Contribution

It provides detailed experimental data on cyclotron resonances in graphite and demonstrates the effectiveness of quasi-classical approaches over quantum perturbative methods in this context.

Findings

Observation of up to twenty cyclotron resonance harmonics

Resonance patterns reflect universal properties near a separatrix

Quasi-classical models better fit experimental data than quantum perturbation approaches

Abstract

Graphite, a model (semi)metal with trigonally warped bands, is investigated with magneto-absorption experiment and viewed as an electronic system in the vicinity of the Lifshitz transition. A characteristic pattern of up to twenty cyclotron resonance harmonics has been observed. This large number of resonances, their relative strengths and characteristic shapes trace the universal properties of the electronic states near a separatrix in the momentum space. Quantum-mechanical perturbative methods with respect to the trigonal warping term hardly describe the data which are, on the other hand, fairly well reproduced within a quasi-classical approach and conventional band structure model. Trigonal symmetry is preserved in graphite in contrast to a similar system, bilayer graphene.