Low-frequency Quantum Oscillations from Interactions in Layered Metals

TL;DR

This paper demonstrates that Coulomb interactions in layered metals can induce low-frequency quantum oscillations in magnetization, revealing interaction effects and explaining recent experimental anomalies.

Contribution

It shows that Coulomb interactions cause additional low-frequency oscillations in layered metals, a novel effect not previously understood.

Findings

Interaction-induced low-frequency oscillations observed

Effect probes short-range Coulomb interactions

Potential explanation for experimental anomalies

Abstract

Metals composed of weakly-coupled, stacked layers possess a Fermi surface that slightly varies in size along the stacking direction. This appears in de Haas-van Alphen (dHvA) oscillations of the magnetisation with magnetic field as two close frequencies, corresponding to the two extremal Fermi surface cross-sectional areas. We show that, for layered materials of sufficiently high mobility, Coulomb interactions can have a dramatic effect on the form of the dHvA oscillations: there is also generically an oscillation at the small difference of the two large frequencies. We determine the size and form of this effect, and show that it probes the short-range part of the Coulomb interactions within the layered material. We argue that this interaction effect may explain recent experimental observations of anomalous low-frequency dHvA oscillations in the ultrapure delafossites.