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arXiv · 2303.00114

Topological Microlaser with A non-Hermitian Topological Bulk

Zhitong Li·Xi-Wang Luo·Dayang Lin·Abouzar Gharajeh·Jiyoung Moon·Junpeng Hou·Chuanwei Zhang·Qing Gu
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Abstract

Bulk-edge correspondence, with quantized bulk topology leading to protected edge states, is a hallmark of topological states of matter and has been experimentally observed in electronic, atomic, photonic, and many other systems. While bulk-edge correspondence has been extensively studied in Hermitian systems, a non-Hermitian bulk could drastically modify the Hermitian topological band theory due to the interplay between non-Hermiticity and topology; and its effect on bulk-edge correspondence is still an ongoing pursuit. Importantly, including non-Hermicity can significantly expand the horizon of topological states of matter and lead to a plethora of unique properties and device applications, an example of which is a topological laser. However, the bulk topology, and thereby the bulk-edge correspondence, in existing topological edge-mode lasers is not well defined. Here, we propose and experimentally probe topological edge-mode lasing with a well-defined non-Hermitian bulk topology in a one-dimensional (1D) array of coupled ring resonators. By modeling the Hamiltonian with an additional degree of freedom (referred to as synthetic dimension), our 1D structure is equivalent to a 2D non-Hermitian Chern insulator with precise mapping. Our work may open a new pathway for probing non-Hermitian topological effects and exploring non-Hermitian topological device applications.

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Zhitong Li, Xi-Wang Luo, Dayang Lin, Abouzar Gharajeh, Jiyoung Moon, Junpeng Hou, Chuanwei Zhang, Qing Gu. 2023-02-28. Topological Microlaser with A non-Hermitian Topological Bulk. https://doi.org/10.1103/physrevlett.131.023202

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