中国物理B ›› 2020, Vol. 29 ›› Issue (12): 120305-.doi: 10.1088/1674-1056/abc0de

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  • 收稿日期:2020-07-14 修回日期:1900-01-01 接受日期:2020-10-14 出版日期:2020-12-01 发布日期:2020-11-13

Peierls-phase-induced topological semimetals in an optical lattice: Moving of Dirac points, anisotropy of Dirac cones, and hidden symmetry protection

Jing-Min Hou(侯净敏)†   

  1. School of Physics, Southeast University, Nanjing 211189, China
  • Received:2020-07-14 Revised:1900-01-01 Accepted:2020-10-14 Online:2020-12-01 Published:2020-11-13
  • Contact: Corresponding author. E-mail: jmhou@seu.edu.cn

Abstract: We propose a square optical lattice in which some of neighbor hoppings have a Peierls phase. The Peierls phase makes the lattice have a special band structure and induces the existence of Dirac points in the Brillouin zone, which means that topological semimetals exist in the system. The Dirac points move with the change of the Peierls phase and the Dirac cones are anisotropic for some vales of the Peierls phase. The lattice has a novel hidden symmetry, which is a composite antiunitary symmetry composed of a translation operation, a sublattice exchange, a complex conjugation, and a local U(1) gauge transformation. We prove that the Dirac points are protected by the hidden symmetry and perfectly explain the moving of Dirac points with the change of the Peierls phase based on the hidden symmetry protection.

Key words: topological semimetal, optical lattice, hidden symmetry

中图分类号:  (Degenerate Fermi gases)

  • 03.75.Ss
02.20.-a (Group theory) 03.65.Vf (Phases: geometric; dynamic or topological) 05.30.Fk (Fermion systems and electron gas)