Frustrated optical lattice: from topological excitations to deconfined phase transition

文:基础院与前沿研究院 图:基础与前沿研究院 / 来源:基础与前沿研究院 / 2019-06-21 / 点击量:1644


  主 题:Frustrated optical lattice: from topological excitations to deconfined phase transition

  时 间:2019年6月27日(周四)14:30

  地 点:沙河校区 通信楼818室

  主讲人:张学锋  教授





  We analyzed the repulsive particles in the frustrated optical lattice. For the triangular lattice, we find two co-order exist phases: supersolid [1] and ordered metals [2]. Both behave like fluid but also keep crystal structure. After introducing the spatial anisotropy, the bosonic domain walls are excited. Such topological defects can continuously change the crystal structure, so that the exotic incommensurate supersolid is observed [3].

  Similar phenomena can also be found in the kagome optical lattice. When choosing cylindrical boundary condition, we found a novel edge liquid phase with fractional charges (spinons) linked by quantum strings (effective gauge field) [4]. In the strong coupling limit, we obtained the effective lattice gauge field theory which shows easy-plane NCCP1 form. And it hints the phase transition from valence bond solid to superfluid can be continuous one which is beyond Ginzburg-Landau symmetry breaking diagram. Recently, such topological phase transition is verified by utilizing large scale quantum Monte Carlo simulations [5].

  [1] X.-F. Zhang, R. Dillenschneider, Y. Yu, and S. Eggert, Phys. Rev. B 84, 174515 (2011)

  [2] L.-F. Tocchio, C. Gros, X.-F. Zhang, and S. Eggert, Phys. Rev. Lett. 113, 246405 (2014)

  [3] X.-F. Zhang, S.-J. Hu, A. Pelster, and S. Eggert, Phys. Rev. Lett. 117, 193201 (2016)

  [4] X.-F. Zhang and S. Eggert, Phys. Rev. Lett. 111, 147201 (2013)

  [5] X.-F. Zhang, Y.-C. He, S. Eggert, R. Moessner, and F. Pollmann, Phys. Rev. Lett. 120, 115702 (2018)



编辑:罗莎  / 审核:罗莎  / 发布者:陈伟