• 文献标题:   Breaking inversion symmetry in a state-dependent honeycomb lattice: artificial graphene with tunable band gap
  • 文献类型:   Article
  • 作  者:   WEINBERG M, STAARMANN C, OLSCHLAGER C, SIMONET J, SENGSTOCK K
  • 作者关键词:   optical lattice, ultracold quantum gase, artificial graphene, excited band, dirac point
  • 出版物名称:   2D MATERIALS
  • ISSN:   2053-1583
  • 通讯作者地址:   Univ Hamburg
  • 被引频次:   10
  • DOI:   10.1088/2053-1583/3/2/024005
  • 出版年:   2016

▎ 摘  要

Here, we present the application of a novel method for controlling the geometry of a state-dependent honeycomb lattice: the energy offset between the two sublattices of the honeycomb structure can be adjusted by rotating the atomic quantization axis. This enables us to continuously tune between a homogeneous graphene-like honeycomb lattice and a triangular lattice and to open an energy gap at the characteristic Dirac points. We probe the symmetry of the lattice with microwave spectroscopy techniques and investigate the behavior of atoms excited to the second energy band. We find a striking influence of the energy gap at the Dirac cones onto the lifetimes of bosonic atoms in the excited band.