Improved selection of dark states in the presence of drive-induced dissipation

We revisit the coherent population trapping (CPT) of a three-state system in the presence of environmental fluctuations and strong electromagnetic driving fields. To this end, we use a fluctuation-regulated quantum master equation that considers the drive-induced dissipation (DID) in the system. The DID originates from the combined effect of a driving field and environmental fluctuations. We report that increasing DID shows a narrowing of CPT linewidth and, hence, improved selection of the dark states. As such, the DID enhances the sensitivity of CPT at a driving strength much larger than the system’s relaxation rates. We also discuss the practical implementation of the scheme along with possible applications.

The figure shows the narrowing of CPT responance (narrow dark region) as the environmental fluctuation correlation \(\tau _c\) and hence, the drive-induced dissipation increases.