Impact of Rb Condensation on Resonant Structures for Microwave Rydberg-Atom Electrometers

This paper discusses resonant cavity sensitivity enhancement of a Rydberg-atom X-band quantum receiver. The vapour cell containing the atoms is placed in a multimode metal waveguide cavity, and here we report a study of the effect of the cell on the resonator. In this work, the waveguide cavity is designed for the 59D5/2 Rydberg state of Rubidium at 10.22 GHz, with frequency tuning capability on the order of tens of MHz to compensate for any detuning due to fabrication. Specifically, inserting the glass vapour cell with Rubidium atoms has an effect on frequency and Q-factor of the cavity, which ultimately affects the receiver sensitivity.