Quantum magneto-oscillations in a two-dimensional Fermi liquid

TL;DR

This paper investigates quantum magneto-oscillations in two-dimensional Fermi liquids, revealing a divergence in effective mass at low temperatures and clarifying the role of interactions and disorder in oscillation amplitudes.

Contribution

It demonstrates that the Lifshitz-Kosevich formula's assumptions break down in 2D, and shows the effective mass diverges logarithmically, extending the Fowler-Prange theorem.

Findings

Effective mass diverges logarithmically at low temperatures.

Quasiparticle lifetime due to inelastic interactions does not affect oscillation amplitude.

Interactions renormalize effective mass but do not influence oscillation damping.

Abstract

Quantum magneto-oscillations provide a powerfull tool for quantifying Fermi-liquid parameters of metals. In particular, the quasiparticle effective mass and spin susceptibility are extracted from the experiment using the Lifshitz-Kosevich formula, derived under the assumption that the properties of the system in a non-zero magnetic field are determined uniquely by the zero-field Fermi-liquid state. This assumption is valid in 3D but, generally speaking, erroneous in 2D where the Lifshitz-Kosevich formula may be applied only if the oscillations are strongly damped by thermal smearing and disorder. In this work, the effects of interactions and disorder on the amplitude of magneto-oscillations in 2D are studied. It is found that the effective mass diverges logarithmically with decreasing temperature signaling a deviation from the Fermi-liquid behavior. It is also shown that the quasiparticle lifetime due to inelastic interactions does not enter the oscillation amplitude, although these interactions do renormalize the effective mass. This result provides a generalization of the Fowler-Prange theorem formulated originally for the electron-phonon interaction.