Title:Oral: Investigating the Purcell Effect in the Vicinity of Exceptional Points

The Purcell effect describes the modification of spontaneous emission rate of an atom due to its coupling with a resonator. In this work, we study the Purcell effect in a system where a transmon qubit is coupled to another transmon-resonator system, which is operated in the vicinity of an exceptional point (EP)—a non-Hermitian degeneracy where eigenvalues and eigenstates coalesce. Through both numerical simulations and experimental measurements, we explore how the proximity to an EP affects the spontaneous emission rate of the qubit. We aim to unravel the interplay between system parameters (e.g. qubit-qubit and the qubit-resonator coupling strengths, resonator dissipation) and non-Hermitian dynamics, leading to novel insights into emission control at or near EPs. These results could have implications in enhancing quantum control in open quantum systems.