Theoretical analysis of an electrometer based on microwave-dressed Rydberg atoms using a quantum interferometer.

Rydberg atoms have demonstrated exceptional capabilities in the precise sensing microwave (MW) fields. Previous studies on Rydberg atom-based electrometers (RAEs) have predominantly focused on absorption measurements. Recently, phase-sensitive RAEs employing Mach-Zehnder interferometer (MZI) have been demonstrated, though their performance remains constrained by the standard quantum limit (SQL). In this study, we combine RAEs with advanced quantum interferometrics to enhance MW field sensing. Within the framework of electromagnetically induced transparency (EIT) and Autler-Townes (AT) splitting, the noise of our enhanced electrometer is suppressed below the photon shot noise (PSN) in measuring light dispersion through microwave-dressed atoms, when utilizing phase squeezed states. In our theory, the optimal sensitivity of the MW field can reach 1.36 × 10V/m/Hz with a dressed MW field strength of 2.4 × 10V/m within a balanced SU(1,1) interferometer.