Microwave cavity searches for low-frequency axion dark matter

Abstract

For low-mass (frequency ≪GHz) axions, dark matter detection experiments searching for an axionphoton-photon coupling generally have suppressed sensitivity, if they use a static background magnetic field. This geometric suppression can be alleviated by using a high-frequency oscillating background field. Here, we present a high-level sketch of such an experiment, using superconducting cavities at ∼GHz frequencies. We discuss the physical limits on signal power arising from cavity properties, and point out cavity geometries that could circumvent some of these limitations. We also consider how backgrounds, including vibrational noise and drive signal leakage, might impact sensitivity. While practical microwave field strengths are significantly below attainable static magnetic fields, the lack of geometric suppression, and higher quality factors, may allow superconducting cavity experiments to be competitive in some regimes.

Detecting High-Frequency Gravitational Waves with Microwave Cavities

“…A similar concept was subsequently applied to the EM signals generated by axion dark matter in Refs. [131][132][133][134]. In a future companion paper, we will extend previous studies to include the direct GW-EM coupling with an oscillating background field, which gives rise to a visible signal also in the idealized case where the cavity is completely isolated from external vibrations.…”

Axion dark matter detection by superconducting resonant frequency conversion

“…Note added: while this study was ongoing, we became aware of ref. [83], which discusses similar ideas for axion detection.…”

More axions from strings

“…The former constrains the maximum value of m r ∆, while the latter imposes a lower bound on H L, where L is the strengthens slightly (up to the edge of the blurred region) for large tan β [70]. The proposed experiments shown are ABRACADABRA [76], superconducting radio frequency cavities "SRF" [77] (see also [78]), CULTASK [79], MADMAX: [80,81], tunable plasma haloscopes "Plasma" [56], TOORAD [55], phase measurements in cavities "phase" [60], absorption by gapped polaritons "polaritons" [57] and IAXO [58]. 19 Many of the details of our implementation follow those described in Appendix A of [7].…”