Detail:
Abstract: Weyl semi-metal (WSM) is a new topological state found recently in condensed matter. In this talk I will introduce the nonmagnetic WSM material TaAs family. From the first principle calculation, we find twelve pairs of Weyl points in the whole Brillouin zone (BZ) of these materials. In the absence of spin-orbit coupling (SOC), band inversions in mirror invariant planes lead to gapless nodal rings in the energy-momentum dispersion. The strong SOC in these materials then opens full gaps in the mirror planes, generating nonzero mirror Chern numbers and Weyl points off the mirror planes. I will also introduce the main physical properties associated with such exotic quantum state including the Fermi arcs on the surface, the negative MR induced by chiral anomaly and the chiral magnetic effect.
