Comparison of Electric Field Sensing using Three-Photon Excitation in Rb and Cs

Rydberg sensing leverages high polarizabilities and large electric dipole moments to produce a precise and compact alternative to classical antennas. The quantum interference phenomenon of Electromagnetically Induced Transparency (EIT) allows small perturbations due to electric fields to be detected optically. The two most commonly employed elements are Cesium (Cs) and Rubidium (Rb). Our work focuses on characterizing the electric field sensing capabilities of both elements. The experiment uses off-resonant AC Stark detection and a heterodyne beatnote configuration, benchmarked by the photon shot noise of the probing laser. Comparative results for Rb and Cs will be presented, informing the fundamental limits of Rydberg sensors going forward.