Searching for axion dark matter with magnetic resonance force microscopy

TL;DR

This paper proposes a novel magnetic resonance force microscopy method to detect axion dark matter around 1 GHz by measuring spin-dependent forces with high sensitivity, enabling competitive constraints with minimal integration time.

Contribution

It introduces a new experimental approach using MRFM to search for axion dark matter and explores its potential to constrain other dark matter couplings.

Findings

Current technology can set competitive constraints with just a minute of data.

The method allows scanning of axion mass by tuning the pump and magnetic fields.

Potential to constrain other dark matter-Standard Model interactions.

Abstract

We propose a magnetic resonance force microscopy (MRFM) search for axion dark matter around 1 GHz. The experiment leverages the axion's derivative coupling to electrons, which induces an effective A.C. magnetic field on a sample of electron spins polarized by a D.C. magnetic field and a micromagnet. A second pump field at a nearby frequency enhances the signal, with the detuning matched to the resonant frequency of a magnet-loaded mechanical oscillator. The resulting spin-dependent force is detected with hih sensitivity via optical interferometry. Accounting for the relevant noise sources, we show that current technology can be used to put constraints competitive with those from laboratory experiments with just a minute of integration time. Furthermore, varying the pump field frequency and D.C. magnetic field allows one to scan the axion mass. Finally, we explore this setup's capability to put constraints on other dark matter - Standard Model couplings.