# Magnetic Bubble Chambers and Sub-GeV Dark Matter Direct Detection

## TL;DR

This paper proposes using single molecule magnet crystals as magnetic bubble chambers to detect sub-GeV dark matter through spin avalanches triggered by dark matter interactions, potentially surpassing current detection sensitivities.

## Contribution

It introduces a novel detector concept utilizing magnetic bubble chambers made from single molecule magnets for direct dark matter detection.

## Key findings

- Potential to detect hidden photon dark matter in the meV - eV range
- Amplification of dark matter signals via magnetic deflagration
- Sensitivity exceeding current bounds by several orders of magnitude

## Abstract

We propose a new application of single molecule magnet crystals: their use as "magnetic bubble chambers" for the direct detection of sub-GeV dark matter. The spins in these macroscopic crystals effectively act as independent nano-scale magnets. When anti-aligned with an external magnetic field they form meta-stable states with a relaxation time that can be very long at sufficiently low temperatures. The Zeeman energy stored in this system can be released through localized heating, caused for example by the scattering or absorption of dark matter, resulting in a spin avalanche (or "magnetic deflagration") that amplifies the effects of the initial heat deposit, enabling detection. Much like the temperature and pressure in a conventional bubble chamber, the temperature and external magnetic field set the detection threshold for a single molecule magnet crystal. We discuss this detector concept for dark matter detection and propose ways to ameliorate backgrounds. If successfully developed, this detector concept can search for hidden photon dark matter in the meV - eV mass range with sensitivities exceeding current bounds by several orders of magnitude.