Comparing Instrument Spectral Sensitivity of Dissimilar Electromagnetic Haloscopes to Axion Dark Matter and High Frequency Gravitational Waves

TL;DR

This paper develops a systematic method to compare the spectral sensitivity of axion haloscopes and gravitational wave detectors, enabling signal-independent instrument comparison and highlighting their potential to detect high frequency gravitational waves and axions.

Contribution

It introduces a new approach to calculate spectral sensitivity of axion haloscopes, facilitating direct comparison with gravitational wave detectors regardless of signal form.

Findings

Spectral sensitivity calculation enables instrument comparison independent of signal assumptions.

The method allows for order-of-magnitude sensitivity comparisons between axion detectors and gravitational wave detectors.

It demonstrates potential for haloscopes to detect high frequency gravitational waves.

Abstract

It is known that haloscopes that search for dark matter axions via the axion-photon anomaly are also sensitive to gravitational radiation through the inverse Gertsenshtein effect. Recently this way of searching for high frequency gravitational waves has gained momentum as it has been shown that the strain sensitivities of such detectors are of the same order of sensitivity to the axion-photon theta angle. Thus, after calculating the sensitivity of a haloscope to an axion signal, we also have calculated the order of magnitude sensitivity to a gravitational wave signal of the same spectral and temporal form. However, it is unlikely that a gravitational wave and an axion signal will be of the same form, since physically the way the signals are generated are completely different. For gravitational wave detection, the spectral strain sensitivity is in units strain per square root Hz, is the natural way to compare the sensitivity of gravitational wave detectors due to its independence on the gravitational wave signal. In this work, we introduce a systematic way to calculate the spectral sensitivity of an axion haloscope, so instrument comparison may be achieved independent of signal assumptions and only depends on the axion to signal transduction sensitivity and noise in the instrument. Thus, the calculation of the spectral sensitivity not only allows the comparison of dissimilar axion detectors independent of signal, but also allows us to compare the order of magnitude gravitational wave sensitivity in terms of spectral strain sensitivity, allowing comparisons to standard gravitational wave detectors based on optical interferometers and resonant-mass technology.