# Modification of the Lifshitz-Kosevich formula for anomalous quantum oscillations in inverted insulators

## TL;DR

This paper analytically demonstrates that quantum oscillations can occur in inverted insulators without a well-defined Fermi surface, modifying the Lifshitz-Kosevich formula to account for such anomalous behavior.

## Contribution

It provides a new analytical formula for quantum oscillations in inverted insulators, extending the Lifshitz-Kosevich theory to systems without a traditional Fermi surface.

## Key findings

- Quantum oscillations are observable in inverted insulators even in the insulating phase.
- The authors derive a modified Lifshitz-Kosevich formula applicable at finite temperatures and in disordered systems.
- Quantum oscillations do not necessarily indicate a well-defined Fermi surface.

## Abstract

It is generally believed that quantum oscillations are a hallmark of a Fermi surface and the oscillations constitute the ringing of it. Recently, it was understood that in order to have well defined quantum oscillations you do not only not need well defined quasiparticles, but also the presence of a Fermi surface is unnecessary. In this paper we investigate such a situation for an inverted insulator from a analytical point of view. Even in the insulating phase clear signatures of quantum oscillations are observable and we give a fully analytical formula for the strongly modified Lifshitz-Kosevich amplitude which applies in the clean as well as the disordered case at finite temperatures.