A New Method for Detecting Axion With Cylindrical Superconductor

TL;DR

This paper proposes a novel method to detect dark matter axions using a cylindrical superconductor under a magnetic field, which generates detectable radiation due to axion-photon conversion.

Contribution

It introduces a new experimental setup employing superconducting cylinders to search for axions via induced oscillating currents and radiation.

Findings

Radiation flux of about 10^{-18} W predicted under specific conditions.

Method enables wide-bandwidth axion search with existing radio telescopes.

Superconducting surface currents are induced by axion-photon conversion in magnetic fields.

Abstract

We propose a method for searching dark matter axion in axion-photon conversion. We consider a superconductor of cylindrical shape under strong magnetic field. The dark matter axion generates oscillating electric field which induces oscillating superconducting current in the surface of the superconductor. The current gives rise to dipole radiation with the frequency $m_a/2\pi$ given by axion mass $m_a$. We show that the radiation flux generated by the current is of the order of $10^{-18}$W under magnetic field $\sim 3$T in the case of radius $\sim 1$cm and length $\sim 10$cm of the cylindrical superconductor. %The superconducting current flows in the surface to the depth $\lambda\simeq 5\times 10^{-6}$cm. The large amount of the radiation flux arises because Cooper pairs with large number density ( $\sim 10^{22}/\rm cm^{3}$ ) is present in the superconductor. With the high detection sensitivity, we can simultaneously search wide bandwidth of the radio frequency with existing radio telescope.