On the phase of magneto-oscillations in graphite

TL;DR

This paper investigates how weak inter-layer interactions in graphite affect magneto-oscillations, revealing anomalies and aperiodicity in the oscillations due to the complex Fermi surface structure.

Contribution

It provides an analytical study showing that inter-layer coupling causes anomalies and aperiodic magneto-oscillations in graphite, extending understanding of Dirac fermions in layered materials.

Findings

Magneto-oscillations are aperiodic due to inter-layer interactions.

Oscillations are asymptotically periodic with phase for massive fermions.

Vanishing inter-layer interaction at the H point yields periodic oscillations.

Abstract

The problem of Dirac fermions in graphite subject to a perpendicular magnetic field is studied. We show analytically that the weak inter-layer interaction between the graphene sheets leads to anomalies in the Shubnikov-de Haas and de Haas-van Alphen magneto-oscillations governed by the orbits around extremal cross-sections of the graphite Fermi surface. The calculation of the Landau plot performed within a four band continuum model reveals that magneto-oscillations are aperiodic, except of the case of vanishing inter-layer interaction at the H point of the graphite Brillouin zone. Also for all other orbits along the H-K-H edge the magneto-oscillations are only asymptotically periodic in the quasi-classical limit, with the phase corresponding to massive fermions.