中国物理B ›› 2017, Vol. 26 ›› Issue (8): 86701-086701.doi: 10.1088/1674-1056/26/8/086701

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Quench dynamics of ultracold atoms in one-dimensional optical lattices with artificial gauge fields

Xiaoming Cai(蔡小明)   

  1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
  • 收稿日期:2016-12-15 修回日期:2017-05-10 出版日期:2017-08-05 发布日期:2017-08-05
  • 通讯作者: Xiaoming Cai E-mail:cxmpx@wipm.ac.cn
  • 基金资助:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11374331, 11304364, and 11534014).

Quench dynamics of ultracold atoms in one-dimensional optical lattices with artificial gauge fields

Xiaoming Cai(蔡小明)   

  1. State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences, Wuhan 430071, China
  • Received:2016-12-15 Revised:2017-05-10 Online:2017-08-05 Published:2017-08-05
  • Contact: Xiaoming Cai E-mail:cxmpx@wipm.ac.cn
  • About author:0.1088/1674-1056/26/8/
  • Supported by:

    Project supported by the National Natural Science Foundation of China (Grant Nos. 11374331, 11304364, and 11534014).

摘要:

We study the quench dynamics of noninteracting ultracold atoms loaded in one-dimensional (1D) optical lattices with artificial gauge fields, which are modeled by lattices with complex hopping coefficients. After suddenly changing the hopping coefficient, time evolutions of the density distribution, momentum distribution, and mass current at the center are studied for both finite uniform systems and trapped systems. Effects of filling factor, system size, statistics, harmonic trap, and phase difference in hopping are identified, and some interesting phenomena show up. For example, for a finite uniform fermionic system shock and rarefaction wave plateaus are formed at two ends, whose wave fronts move linearly with speed equaling to the maximal absolute group velocity. While for a finite uniform bosonic system the whole density distribution moves linearly at the group velocity. Only in a finite uniform fermionic system there can be a constant quasi-steady-state current, whose amplitude is decided by the phase difference and filling factor. The quench dynamics can be tested in ultracold atoms with minimal modifications of available experimental techniques, and it is a very interesting and fundamental example of the transport phenomena and the nonequilibrium dynamics.

关键词: nonequilibrium dynamics, 1D optical Lattice, artificial gauge field, quasi-steady-state current

Abstract:

We study the quench dynamics of noninteracting ultracold atoms loaded in one-dimensional (1D) optical lattices with artificial gauge fields, which are modeled by lattices with complex hopping coefficients. After suddenly changing the hopping coefficient, time evolutions of the density distribution, momentum distribution, and mass current at the center are studied for both finite uniform systems and trapped systems. Effects of filling factor, system size, statistics, harmonic trap, and phase difference in hopping are identified, and some interesting phenomena show up. For example, for a finite uniform fermionic system shock and rarefaction wave plateaus are formed at two ends, whose wave fronts move linearly with speed equaling to the maximal absolute group velocity. While for a finite uniform bosonic system the whole density distribution moves linearly at the group velocity. Only in a finite uniform fermionic system there can be a constant quasi-steady-state current, whose amplitude is decided by the phase difference and filling factor. The quench dynamics can be tested in ultracold atoms with minimal modifications of available experimental techniques, and it is a very interesting and fundamental example of the transport phenomena and the nonequilibrium dynamics.

Key words: nonequilibrium dynamics, 1D optical Lattice, artificial gauge field, quasi-steady-state current

中图分类号:  (Ultracold gases, trapped gases)

  • 67.85.-d
05.60.Gg (Quantum transport) 72.10.-d (Theory of electronic transport; scattering mechanisms) 67.10.Jn (Transport properties and hydrodynamics)