Broadband and Resonant Approaches to Axion Dark Matter Detection
Abstract
When ultralight axion dark matter encounters a static magnetic field, it sources an effective electric current that follows the magnetic field lines and oscillates at the axion Compton frequency. We propose a new experiment to detect this axion effective current. In the presence of axion dark matter, a large toroidal magnet will act like an oscillating current ring, whose induced magnetic flux can be measured by an external pickup loop inductively coupled to a SQUID magnetometer. We consider both resonant and broadband readout circuits and show that a broadband approach has advantages at small axion masses. We estimate the reach of this design, taking into account the irreducible sources of noise, and demonstrate potential sensitivity to axion-like dark matter with masses in the range of 10^{-14}-10^{-6} eV. In particular, both the broadband and resonant strategies can probe the QCD axion with a GUT-scale decay constant.
Keywords
Cite
@article{arxiv.1602.01086,
title = {Broadband and Resonant Approaches to Axion Dark Matter Detection},
author = {Yonatan Kahn and Benjamin R. Safdi and Jesse Thaler},
journal= {arXiv preprint arXiv:1602.01086},
year = {2016}
}
Comments
5+3 pages, 3 figures. v3: approximate version to appear in PRL. v2: Minor clarifications throughout, references added, improved discussion of pickup loop inductance and low-frequency reach, title and abstract modified to reflect complementarity of broadband/resonant strategies, conclusions unchanged