Sensitivity comparison of two-photon vs three-photon Rydberg electrometry
Nikunjkumar Prajapati, Narayan Bhusal, Andrew P. Rotunno, Samuel Berweger, Matthew T. Simons, Alexandra B. Artusio‐Glimpse, Ying Ju Wang, Eric Bottomley, Haoquan Fan, Christopher L. Holloway
Abstract
We investigate the sensitivity of co-linear three-photon electromagnetically induced transparency (EIT) in 133Cs Rydberg atoms to radio frequency electric fields and compare against the conventional two-photon system. Specifically, we model the 4-level and 5-level atomic systems and compare how the transmission of the probe changes with different laser powers and RF field strengths. In this model, we define a sensitivity metric that relates to the current best experimental implementation and assumes photon shot noise limited detection. We find that the three-photon system boasts much narrower linewidths compared to the conventional two-photon EIT. These narrow line features, however, do not align with the regions of the best sensitivity. In addition to this, we calculate the expected sensitivity for the two-photon Rydberg sensor and find that the best achievable sensitivity is over an order of magnitude better than the current measured values of 5 μVm−1Hz−1/2. However, by accounting for additional noise sources in the experiment and the quantum efficiency of the photo-detectors, the values are in good agreement.