Quantum non-demolition measurement of microwave field based on atomic superhet

Abstract

The thermal-vapor-cell-based atomic radio frequency electric field (RF E-field) measurement technique has developed rapidly. At present, two types of atom-based electric field sensors: atomic electrometer [Nat. Phys. 8(11), 819-824], and atomic superhet [Nat. Phys. 16, 911–915] have been realized. Here, we discuss the most significant advantage of atomic sensors over traditional sensors: the measurement of E-fields by atomic sensors is non-demolition, while conventional sensors are passive and destructive. QND measurement characteristics of an atomic sensor can well combine with the cavity-enhanced technique; thus, the combined system, e.g., a cavity-enhanced atomic superhet, may achieve a measurement sensitivity beyond the traditional system. This powerful sensor will have important applications in many fields, including cosmology, wireless communication, and remote sensing.