HEPL Seminar-Nov 2, 2022 HEPL Seminar Wednesday, November 2, 2022 3:00pm Physics and Astrophysics Conference rooms 102/103 Speaker: Yuqi Zhu From: Yale University Title: Toward Rydberg atom-based single-microwave-photon detection in an axion search Abstract: The axion is a well-motivated solution to the strong charge–parity problem in quantum chromodynamics, and is also a dark matter candidate. It couples extremely weakly to standard model particles and can take on a wide range of masses; both make its direct detection challenging. The most sensitive laboratory experiments, including ADMX, CAPP, and HAYSTAC, make use of the haloscope technique based on axion-photon conversion. Owing to low-noise amplifiers, they are sensitive to microwave powers on the order of 10-24 W in the 0.5-5 GHz range. The field is working on extending axion searches out to 50 GHz (equivalent to 200 μeV) with a similar sensitivity. I will discuss our proposed scheme for Rydberg atom-based single-microwave-photon detectors in high-mass haloscope searches and show some spectroscopy results that allow us to identify relevant Rydberg states in potassium.