Quantum Measurement Induced Radiative Processes in Continuously Monitored Optical Environments

We investigate the emission characteristics of a measurement-driven quantum emitter in a continuously monitored optical environment. The quantum emitter is stimulated by observing the Pauli spin along its transition dipole that maximally non-commutes with the Hamiltonian of the emitter. It also exchanges energy resonantly with the optical environment, observable as quantum jumps corresponding to the absorption or emission of a photon and the null events where the quantum emitter did not make a jump. We characterize the finite-time statistics of quantum jumps and estimate their covariance and precision using the large deviation principle. We also generalize our considerations to coarse-grained measurements of the optical field and compute the finite-time statistics of the sum of absorption and emission events, which we refer to as the negation of null events in our problem. While the statistics of absorption and emission events are generically sub-Poissonian, our analysis reveals a spin-measurement-induced transition from super-Poissonian to sub-Poissonian in their sum. Our findings suggest that quantum measurement-induced fluctuations can be a useful alternative to coherent drives for stimulating radiative transitions having controllable emission characteristics, with implications extending to atomic and nuclear clocks.