Past Events

back to listing

Topological Quantum Gas with Spin-Orbit Coupling


Speaker:Prof. Shuai Chen
Affiliation:University of Science and Technology of China
Date:August 22, 2019 (Thursday)
Time:2:30 p.m.
Venue:Room 522, 5/F, Chong Yuet Ming Physics Building, HKU

Abstract


Spin-Orbit (SO) coupling, as a fundamental quantum effect, is an essential ingredient in many topological phases of quantum matters, like topological insulator and topological semiconductor. To synthesize high-dimensional (2D or higher) SO coupling with ultracold quantum gases is one of the keys for studying topological quantum matters in the field of quantum simulation. We report here the realization of a robust and highly controllable 2D SO coupling with topological non-trivial band structure. By applying a retro-reflected 2D optical lattice, the synthesized 2D SO coupling has precise inversion and C4 symmetries. The non-trivial band topology of the 2D SO coupling are precisely addressed by both equilibrium and non-equilibrium processes. By applying the quantum quench dynamics along each spin axis, the dynamical bulk-ring correspondence of the topological quantum matter is well demonstrated, and topological charges are also observed from the the post-quench evolution of the spin texture. Our studies open the new avenue in quantum simulation to explore exotic topological matters with non-equilibrium dynamics.

References:
1. Zhan Wu, Long Zhang, Wei Sun, Xiao-Tian Xu, Bao-Zong Wang, Si-Cong Ji, Youjin Deng, Shuai Chen, Xiong-Jun Liu, and Jian-Wei Pan, Realization of two-dimensional spin-orbit coupling for Bose-Einstein condensates, Science 354, 83 (2016)
2. Wei Sun, Bao-Zong Wang, Xiao-Tian Xu, Chang-Rui Yi, Long Zhang, Zhan Wu, Youjin Deng, Xiong-Jun Liu, Shuai Chen, and Jian-Wei Pan, Highly Controllable and Robust 2D Spin-Orbit Coupling for Quantum Gases, Physical Review Letters 121, 150401 (2018)
3. Wei Sun, Chang-Rui Yi, Bao-Zong Wang, Wei-Wei Zhang, Barry C. Sanders, Xiao-Tian Xu, Zong-Yao Wang, Joerg Schmiedmayer, Youjin Deng, Xiong-Jun Liu, Shuai Chen and Jian-Wei Pan, Uncover Topology by Quantum Quenching Dynamics, Physical Review Letters 121, 250403 (2018)
4. Chang-Rui Yi, Long Zhang, Lin Zhang, Rui-Heng Jiao, Zong-Yao Wang, Xiao-Tian Xu, Wei Sun, Xiong-Jun Liu, Shuai Chen and Jian-Wei Pan, Observing topological charges and dynamical bulk-ring correspondence with ultracold atoms, arXiv: 1905.06478

Coffee and tea will be served 20 minutes prior to the seminar.

Anyone interested is welcome to attend.