Loss-induced phenomena in cavity QED systems

Cavity quantum electrodynamical (QED) systems, in which a confined light in a cavity interacts with a quantum emitter, hold great promise for a wide range of applications, from quantum information [Rev. Mod. Phys. 87, 1379 (2015)] to polaritonic chemistry [Chemical Reviews 123.16, 9786-9879 (2023)]. These systems are typically lossy due to the imperfection of the cavity that enables leakage of the light outside the cavity. While these losses often limit the applicability of cavity QED systems, here we focus on exploring novel phenomena arising from the lossy nature of cavity QED systems. For that, we use the non-Hermitian formalism, which has attracted much attention recently and enables revealing effects that are hidden in the standard formalism [Nature (London) 537, 76 (2016)]. We show that the losses can be utilized to generate single-photon emission through a novel mechanism [Phys. Rev. Lett. 130, 243601 (2023)], converting a non-Markovian bath to Markovian, etc.