Work

Chiral exceptional bound states in the continuum: A higher-order singularity for on-chip control of quantum emission

Year: 2026

Type: article

Abstract: We demonstrate a fully integrable and reconfigurable platform for controlling quantum emission by harnessing chiral exceptional bound states in the continuum (BICs) as a higher-order non-Hermitian singularity. Our architecture employs dual-microring resonators evanescently coupled to two waveguides, supporting symmetry-protected BICs. By integrating a waveguide-coupled reflector coupled with one resonator as a unidirectional feedback, a pair of orthogonal BICs gets transformed into a single, chiral quasi-BIC residing on an exceptional surface. The phase terms in external coupling and intermodal coupling serve as two independent tuning knobs, enabling unprecedented dynamic control over the spontaneous emission dynamics of individual quantum emitters, including the Purcell enhancement and the emission line shape. The efficiency in reconfiguring the output intensity gets promoted by more than a factor of two compared to alternative schemes, offering a promising path toward high-speed quantum optical switches and active lifetime control in integrated quantum photonic circuits.

Source: Physical Review Research

DOI: 10.1103/5mpf-rfj5

Authors: Jin Li, Kexun Wu, Qi Hao, Yan Chen, Jiawei Wang

Institutions: Harbin Institute of Technology, Southeast University, National University of Defense Technology

Language: English

Topic: Quantum Mechanics and Non-Hermitian Physics

Subfield: Atomic and Molecular Physics, and Optics

Field: Physics and Astronomy

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,625

Funders: National Natural Science Foundation of China, Science, Technology and Innovation Commission of Shenzhen Municipality, Basic and Applied Basic Research Foundation of Guangdong Province