Time: 9:30am, Nov. 18, 2019

Venue: Rm. S401, Kavli ITS Meeting Room

Speaker: Chen Peng (Renmin Univ.)

Abstract:

The interplay between interaction and the topological system could result in exotic phases or phase transition, which beyond the mean-field approach. In the first example, we apply cluster charge interaction to Kane-mele Model. Since the interactions do not break the symmetry that protects the topology, we derive an exotic nontrivial phase, which could coexist with the KVBS long-range order. After an elaborative numerical simulation,  we find the topological phase transition does not have a non-interacting counterpart. In the second part, I will give a short introduction to a typical high-order topological insulator named topological quadrupole insulator. Through our numerical simulation, correlation effects are studied for the first time in this system. And we find a HOTI-AFM topological phase transition driven by Hubbard interactions, which gives critical exponents that deviated from the O3 universality class.