Axion search with quantum nondemolition detection of magnons

TL;DR

This paper proposes a novel quantum nondemolition detection method for axions using magnon detection in a solid-state system, combining a ferrimagnetic sphere and superconducting qubit inside a microwave cavity to search for axion-electron interactions.

Contribution

It introduces a new axion detection scheme based on quantum nondemolition measurement of magnons, utilizing a ferrimagnetic sphere and superconducting qubit inside a microwave cavity.

Findings

Set an upper limit for the axion-electron coupling constant as $g_{aee}<2.6\times10^{-6}$.

Demonstrated the feasibility of detecting axions in the mass range around 33.1 μeV.

Proposed a prototype detector integrating solid-state spin systems and quantum measurement techniques.

Abstract

The axion provides a solution for the strong CP problem and is one of the leading candidates for dark matter. This paper proposes an axion detection scheme based on quantum nondemolition detection of magnon, i.e., quanta of collective spin excitations in solid, which is expected to be excited by the axion-electron interaction predicted by the Dine-Fischer-Srednicki-Zhitnitsky (DFSZ) model. The prototype detector is composed of a ferrimagnetic sphere as an electronic spin target and a superconducting qubit. Both of these are embedded inside a microwave cavity, which leads to a coherent effective interaction between the uniform magnetostatic mode in the ferrimagnetic crystal and the qubit. An upper limit for the coupling constant between an axion and an electron is obtained as $g_{aee}<2.6\times10^{-6}$ at the 95% confidence level for the axion mass of $33.117$$\mu$eV $<m_{a}<33.130$$\mu$eV.