Dressed bound states at chiral exceptional points
Yuwei Lu, Haishu Tan, Zeyang Liao
Abstract
Atom-photon dressed states are a basic concept of quantum optics. Here, we demonstrate that the non-Hermiticity of an open cavity can be harnessed to form the dressed bound states (DBSs) and identify two types of DBSs, the vacancylike DBS and Friedrich-Wintgen DBS, in a microring resonator operating at a chiral exceptional point. With the analytical DBS conditions, we show that the vacancylike DBS occurs when an atom couples to the standing-wave mode that is a node of the photonic wave function and characterized by null spectral density at cavity resonance. However, the Friedrich-Wintgen DBS can be accessed by continuously tuning the system parameters, such as the atom-photon detuning, and evidenced by a vanishing Rabi peak in the emission spectrum, an unusual feature in the strong-coupling anticrossing. We also demonstrate the quantum-optics applications of the proposed DBSs. Our work exhibits quantum state control through non-Hermiticity of open quantum system and presents a clear physical picture of DBSs at chiral exceptional points, which holds great potential for building high-performance quantum devices for sensing, photon storage, and nonclassical light generation.