Trap-loss fluorescence spectroscopy of cesium magneto-optical trap with single-photon Rydberg excitation and the background electric field measurement and regulation.

Calibration and compensation of the background electric fields in the vicinity of the cold atomic ensemble are critically vital, for achieving quantum computing, quantum simulation, and precision measurement. Here the work presents and demonstrates a straightforward method for measuring and compensation of the background electric field by means of the trap-loss fluorescence spectroscopy (TLFS) of cesium (Cs) magneto-optical trap (MOT) with the Rydberg P states with principal quantum numbers from 71 to 85. In our experiment, TLFS is induced by single-photon Rydberg excitation with a Cs MOT, utilizing a 319 nm ultraviolet (UV) laser characterized by narrow linewidth (less than 6 kHz), continuous fine-tuning of 1 GHZ, and ultra-low-intensity noise (the intensity fluctuates approximately ±0.06 over 25 minutes with sampling power of 3 mW). Using this method, we measure the intensity of the background electric field in the vicinity of a cold atomic ensemble of about 218.9 ± 7.5 mV/cm. Through adjustment of electrode plates the residual electric field was reduced to 116.3 mV/cm, which induces a Stark shift -84.1 MHz. Our experiments provide an easier and more straightforward method for measuring and regulating the background electric field and lay a foundation for optimizing electric field compensation and fast feedback systems in the future.