Searching for axions with quantum interferometry

TL;DR

This paper proposes quantum interferometry techniques, including Aharonov-Bohm and Berry phase measurements, as promising new methods for detecting axions and axion-like particles, with potential to surpass current experimental bounds.

Contribution

It introduces novel quantum phase measurement schemes for axion detection, demonstrating their sensitivity and potential advantages over existing methods.

Findings

AB phase search can improve sensitivity to axion-photon coupling by 1-2 orders of magnitude.

A geometric phase in a Mach-Zehnder interferometer can probe meV-scale axions.

A three-level photon-axion quasiparticle system shows measurable Berry phases, validating the formalism.

Abstract

Quantum phase measurements offer a complementary route to axion searches. We show that axion-photon interactions can imprint both Aharonov-Bohm (AB) and Berry phases in experimentally motivated quantum setups. For a coherently oscillating axion dark matter background, the induced effective current generates a time dependent magnetic flux in an rf-SQUID, leading to a measurable voltage signal through the Josephson phase. For representative benchmarks, this AB phase search reaches the minimum axion-photon coupling $g_{a\gamma\gamma}^{\mathrm{min}}\sim 7.8\times10^{-14}~\mathrm{GeV}^{-1}$ at axion mass $m_a\sim 10^{-10}~\mathrm{eV}$, with projected sensitivity that can improve on existing limits in that parameter space by roughly one to two orders of magnitude. We also identify a geometric phase observable in a Mach-Zehnder interferometer with an adiabatically rotating magnetic field, providing a proof-of-principle phase-based probe of meV-scale axions even when they do not constitute the dark matter, although sensitivity on the coupling remains weaker than current bounds with conservative tabletop benchmarks. Extending the analysis to a three level photon-axion quasiparticle (AQP)-axion system, with the AQP realized in a topological magnetic insulator, we find a potentially measurable THz Berry phase dominated by the AQP sector, furnishing a nontrivial validation of the formalism in a richer coupled system. These setups establish quantum phase observables as a useful new framework for axion searches, with immediate phenomenological promise in superconducting circuits and longer term potential in quantum enhanced interferometry.