Professor, School of Materials Science and Engineering, Harbin Institute of Technology (Shenzhen), China.

Speech Title: Quantum effects in ferromagnetic topological insulators and low-dimensional superconductors
Abstract:Quantum anomalous Hall (QAH) effect in ferromagnetic topological insulator was first reported in 2013. In this talk, I will introduce the experimental observation of the high precision realization of QAH state in V-doped (Bi,Sb)₂Te₃ films. Hall resistance of 1.00019±0.00069h/e² (25.8178±0.0177kΩ) and the zero-field longitudinal resistance down to 0.00013±0.00007h/e² (~3.35±1.76Ω) at T=25mK was found in this material. The zero-field dissipationless chiral edge transport has unambiguously been established by a comprehensive experimental study of the gate and temperature dependences of local and nonlocal magnetoresistance in the same system. I will also introduce several quantum effects in new high-quality low-dimensional superconducting systems including superlong superconducting nanowires and atomic flat single crystal superconducting films. These quantum effects, which can't be observed in the bulk superconductor, include quantum phase slip, single fluxon resistance switch, Kosterlitz-Thouless transition, vortex phase transition and Ising pair.