报告题目：Isotropic Landau levels of relativistic and non-relativistic fermions in 3D flat space

报 告 人：Yi Li, University of California, San Diego

报告时间：8月30日（星期二）上午10：30

报告地点：理科楼B-406

报告摘要：We generalize the two-dimensional Landau level problem to three dimensions and above for both the relativistic and non-relativistic cases. For the 3D case filled with fermions, the systems are topological insulators belong to the Z2-class. The non-relativistic case is a problem of spin-1/2 fermions coupling to the Aharanov-Casher SU(2) gauge field. They exhibit flat Landau levels in which orbital angular momentum and spin are coupled with a fixed helicity. In spite of the intrinsic spatial inhomogeneity, magnetic translations can be defined for the highest weight states of the total angular momentum. Each Landau level contributes one branch of gapless helical Dirac channel to the surface spectra, whose topological properties belong to the $\mathbb{Z}_{2}$-class. This problem can be further generalized to Dirac fermions, which is essentially a square root problem of the previous version. Each zero energy Landau level state is a half-fermion mode.