title: Realization of two-dimensional spin-orbit coupling for Bose-Einstein condensates.
abstract: Cold atoms with laser-induced spin-orbit (SO) interactions provide a platform to explore quantum physics beyond natural conditions of solids. Here we propose and experimentally realize two-dimensional (2D) SO coupling and topological bands for a rubidium-87 degenerate gas through an optical Raman lattice, without phase-locking or fine-tuning of optical potentials. A controllable crossover between 2D and 1D SO couplings is studied, and the SO effects and nontrivial band topology are observed by measuring the atomic cloud distribution and spin texture in momentum space. Our realization of 2D SO coupling with advantages of small heating and topological stability opens a broad avenue in cold atoms to study exotic quantum phases, including topological superfluids.
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China.|Chinese Academy of Sciences (CAS) Center for Excellence and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|CAS-Alibaba Quantum Computing Laboratory, Shanghai 201315, China.
authors.forename: Zhan
authors.initials: Z
authors.lastname: Wu
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China.|International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.|Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
authors.forename: Long
authors.initials: L
authors.lastname: Zhang
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China.|Chinese Academy of Sciences (CAS) Center for Excellence and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|CAS-Alibaba Quantum Computing Laboratory, Shanghai 201315, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Sun
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China.|Chinese Academy of Sciences (CAS) Center for Excellence and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|CAS-Alibaba Quantum Computing Laboratory, Shanghai 201315, China.
authors.forename: Xiao-Tian
authors.initials: XT
authors.lastname: Xu
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China.|International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China.|Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
authors.forename: Bao-Zong
authors.initials: BZ
authors.lastname: Wang
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China.|Chinese Academy of Sciences (CAS) Center for Excellence and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.
authors.forename: Si-Cong
authors.initials: SC
authors.lastname: Ji
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China.|Chinese Academy of Sciences (CAS) Center for Excellence and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|CAS-Alibaba Quantum Computing Laboratory, Shanghai 201315, China.
authors.forename: Youjin
authors.initials: Y
authors.lastname: Deng
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China. shuai@ustc.edu.cn xiongjunliu@pku.edu.cn pan@ustc.edu.cn.|Chinese Academy of Sciences (CAS) Center for Excellence and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|CAS-Alibaba Quantum Computing Laboratory, Shanghai 201315, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Chen
authors.affiliation: International Center for Quantum Materials, School of Physics, Peking University, Beijing 100871, China. shuai@ustc.edu.cn xiongjunliu@pku.edu.cn pan@ustc.edu.cn.|Collaborative Innovation Center of Quantum Matter, Beijing 100871, China.
authors.forename: Xiong-Jun
authors.initials: XJ
authors.lastname: Liu
authors.affiliation: Shanghai Branch, National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Shanghai 201315, China. shuai@ustc.edu.cn xiongjunliu@pku.edu.cn pan@ustc.edu.cn.|Chinese Academy of Sciences (CAS) Center for Excellence and Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026, China.|CAS-Alibaba Quantum Computing Laboratory, Shanghai 201315, China.
authors.forename: Jian-Wei
authors.initials: JW
authors.lastname: Pan