Topological phase transition induced by gain and loss in a photonic Chern insulator

• Main Authors: Teo, Hau Tian, Xue, Haoran, Zhang, Baile
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2022
• Subjects: Science::Physics; Photonic Devices; Field Distribution
• Online Access: https://hdl.handle.net/10356/161003
• Institution: Nanyang Technological University

We present a design of a non-Hermitian photonic Chern insulator whose band topology can be tuned via gain and loss. It is found that, by continuously varying the gain and loss parameter, a topological phase transition can take place in the photonic crystal, accompanied by the closing and reopening of a Dirac cone. We demonstrate this phenomenon through numerical simulations of the bulk and the edge dispersions, and steady field distributions excited by a point source. Our results show the possibility of non-Hermitian control over band topology in a Chern insulator setting and may find applications in active topological photonic devices.