# Diamond Detectors for Direct Detection of Sub-GeV Dark Matter

## TL;DR

This paper explores using high-purity diamond detectors to detect sub-GeV dark matter through nuclear and electron recoils, offering improved sensitivity to low-mass dark matter and axion-like particles.

## Contribution

It introduces diamond as a novel detector material capable of probing lower dark matter masses and axion parameters compared to existing semiconductors.

## Key findings

- Diamond detectors can detect dark matter with masses down to sub-eV.
- They offer comparable electron recoil sensitivity to germanium and silicon.
- Diamond's properties enable better control of dark counts.

## Abstract

We propose to use high-purity lab-grown diamond for the detection of sub-GeV dark matter. Diamond targets can be sensitive to both nuclear and electron recoils from dark matter scattering in the MeV and above mass range, as well as to absorption processes of dark matter with masses between sub-eV to 10's of eV. Compared to other proposed semiconducting targets such as germanium and silicon, diamond detectors can probe lower dark matter masses via nuclear recoils due to the lightness of the carbon nucleus. The expected reach for electron recoils is comparable to that of germanium and silicon, with the advantage that dark counts are expected to be under better control. Via absorption processes, unconstrained QCD axion parameter space can be successfully probed in diamond for masses of order 10 eV, further demonstrating the power of our approach.