We provide a comprehensive comparison of linear amplifiers and microwave photon-counters in axion dark matter experiments. The study is done assuming a range of realistic operating conditions and detector parameters, over the frequency range between 1--30 GHz. As expected, photon counters are found to be advantageous under low background, at high frequencies (ν> 5 GHz), if they can be implemented with robust wide-frequency tuning or a very low dark count rate. Additional noteworthy observations emerging from this study include: (1) an expanded applicability of off-resonance photon background reduction, including the single-quadrature state squeezing, for scan rate enhancements; (2) a much broader appeal for operating the haloscope resonators in the over-coupling regime, up to β∼10; (3) the need for a detailed investigation into the cryogenic and electromagnetic conditions inside haloscope cavities to lower the photon temperature for future experiments; (4) the necessity to develop a distributed network of coupling ports in high-volume axion haloscopes to utilize these potential gains in the scan rate.
@article{arxiv.2411.13776,
title = {Maximizing Quantum Enhancement in Axion Dark Matter Experiments},
author = {Chao-Lin Kuo and Chelsea L. Bartram and Aaron S. Chou and Taj A. Dyson and Noah A. Kurinsky and Gray Rybka and Sephora Ruppert and Osmond Wen and Matthew O. Withers and Andrew K. Yi and Cheng Zhang},
journal= {arXiv preprint arXiv:2411.13776},
year = {2025}
}