Quantum oscillations in the activated conductivity in excitonic insulators: possible application to monolayer WTe2

TL;DR

This paper proposes a conventional explanation for quantum oscillations observed in monolayer WTe2's insulating state, suggesting gap modulation in an excitonic insulator model as an alternative to exotic physics.

Contribution

It introduces a gap modulation model in excitonic insulators to explain quantum oscillations in monolayer WTe2, challenging the need for exotic physics explanations.

Findings

Quantum oscillations can arise from gap modulation in excitonic insulators.

The model explains periodic conductivity oscillations in 1/B.

Conventional physics may account for phenomena previously attributed to exotic effects.

Abstract

A recent paper on the insulating state of monolayer WTe2 reported the observation of large oscillations in the conductivity that are periodic in 1/B, resembling quantum oscillations in metals. This remarkable observation has inspired suggestions of exotic physics such as spin-charge separation. We show that a rather more conventional but still nontrivial explanation in terms of gap modulation may be possible in a model of excitonic insulator subject to a magnetic field.