Mass fluctuations and absorption rates in Dirac materials sensors

TL;DR

This paper investigates how mass fluctuations in gapped Dirac materials affect their interband absorption, which is crucial for their use as dark matter sensors, by modeling disorder effects on the density of states.

Contribution

It introduces a framework to analyze the impact of both continuous and discrete mass fluctuations on the absorption properties of Dirac materials used in dark matter detection.

Findings

Mass fluctuations create Lifshitz tails in the density of states.

Disorder-induced gap filling affects sensor performance.

The framework models arbitrary disorder mechanisms on absorption rates.

Abstract

We study the mass fluctuations in gapped Dirac materials by treating the mass-term as both a continuous and discrete random variable. Gapped Dirac materials were proposed to be used as materials for Dark matter sensors. One thus would need to estimate the role of disorder and fluctuations on the interband absorption of dark matter. We find that both continuous and discrete fluctuations across the sample introduce tails (e.g. Lifshitz tails) in the density of states and the interband absorption rate. We estimate the strength of the gap filling and discuss implications of these fluctuations on the performance as sensors for Dark matter detection. The approach used in this work provides a basic framework to model the disorder by any arbitrary mechanism on the interband absorption of Dirac material sensors.