Free University Berlin, Germany

摘要：Topological insulators and their intriguing edge states can be understood in a single-particle picture. Interactions significantly complicate this picture and can lead to entirely new phases. Most saliently, when interacting particles in a two-dimensional lattice partially fill in a flat Bloch band with non-zero Chern number, new topological phases can emerge which are called as fractional Chern insulators. In this talk, I will start from tight-binding models hosting nearly flat bands with non-zero Chern number, then summarize the present understanding of fractional Chern insulators within these bands based on numerical techniques such as exact diagonalization and DMRG. Furthermore, I will compare fractional Chern insulators with other interacting phases, such as two-dimensional continuum fractional quantum Hall states, the interacting phases in Fermi arcs of three-dimensional Weyl semimetals, and some gapped phases in one-dimensional lattices.
刘钊2007年南京大学毕业，2012年中科院物理研究所获得博士学位，2012-2015分别在北京计算科学中心、美国普林斯顿大学和德国柏林自由大学做博士后研究工作。

References:
[1] Zhao Liu, Emil J. Bergholtz, Heng Fan, and Andreas M. Laeuchli, Fractional Chern insulators in topological flat bands with higher Chern number, Phys. Rev. Lett. 109, 186805 (2012).
[2] Andreas M. Laeuchli, Zhao Liu, Emil J. Bergholtz, and R. Moessner, Hierarchy of fractional Chern insulators and competing compressible states, Phys. Rev. Lett. 111, 126802 (2013).
[3] Dong Wang, Zhao Liu, Junpeng Cao, and Heng Fan, Tunable band topology reflected by fractional quantum Hall states in two-dimensional lattices, Phys. Rev. Lett. 111, 186804 (2013).
[4] E. J. Bergholtz, Zhao Liu, M. Trescher, R. Moessner, and M. Udagawa, Topology and Interactions in a Frustrated Slab: Tuning from Weyl Semimetals to C > 1 Fractional Chern Insulators, Phys. Rev. Lett. 114, 016806 (2015).
[5] Emil J. Bergholtz and Zhao Liu: Topological flat band models and fractional Chern insulators, Int. J. Mod. Phys. B 27, 1330017 (2013).

报告邀请人：范桁 研究员
联系人：刘青梅（9414）