Topological band structure via twisted photons in a degenerate cavity

Mu Yang; Hao-Qing Zhang; Yu-Wei Liao; Zheng-Hao Liu; Zheng-Wei Zhou; Xing-Xiang Zhou; Jin-Shi Xu; Yong-Jian Han; Chuan-Feng Li; Guang-Can Guo

doi:10.1038/s41467-022-29779-3

Topological band structure via twisted photons in a degenerate cavity

Nat Commun. 2022 Apr 19;13(1):2040. doi: 10.1038/s41467-022-29779-3.

Authors

Mu Yang^#^{1

2}, Hao-Qing Zhang^#^{1

2}, Yu-Wei Liao^#^{1

2}, Zheng-Hao Liu^{1

2}, Zheng-Wei Zhou^{1

2}, Xing-Xiang Zhou^{1

2}, Jin-Shi Xu^{3

4}, Yong-Jian Han^{5

6}, Chuan-Feng Li^{7

8}, Guang-Can Guo^{1

2}

Affiliations

¹ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, 230026, PR China.
² CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, PR China.
³ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, 230026, PR China. jsxu@ustc.edu.cn.
⁴ CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, PR China. jsxu@ustc.edu.cn.
⁵ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, 230026, PR China. smhan@ustc.edu.cn.
⁶ CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, PR China. smhan@ustc.edu.cn.
⁷ CAS Key Laboratory of Quantum Information, University of Science and Technology of China, Hefei, 230026, PR China. cfli@ustc.edu.cn.
⁸ CAS Center For Excellence in Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, 230026, PR China. cfli@ustc.edu.cn.

^# Contributed equally.

Abstract

Synthetic dimensions based on particles' internal degrees of freedom, such as frequency, spatial modes and arrival time, have attracted significant attention. They offer ideal large-scale lattices to simulate nontrivial topological phenomena. Exploring more synthetic dimensions is one of the paths toward higher dimensional physics. In this work, we design and experimentally control the coupling among synthetic dimensions consisting of the intrinsic photonic orbital angular momentum and spin angular momentum degrees of freedom in a degenerate optical resonant cavity, which generates a periodically driven spin-orbital coupling system. We directly characterize the system's properties, including the density of states, energy band structures and topological windings, through the transmission intensity measurements. Our work demonstrates a mechanism for exploring the spatial modes of twisted photons as the synthetic dimension, which paves the way to design rich topological physics in a highly compact platform.