报告题目：Materials Physics for Dirac Fermion-Based Electronics

报 告 人：Shengbai Zhang，Rensselaer Polytechnic Institute, Troy, NY, US

报告时间：5月31日 （周四）11:00-12:00

报告地点：物理系三层会议室

报告摘要：Today’s electronics is based on semiconductors with parabolic energy dispersions near the band gap. Recently, Dirac fermions, where the energy dispersion near the Fermi level is linear, have attracted considerable attention for their unique electronic properties and, to some degree, the dream of performing particle physics on desktop. Two noticeable examples are the topological insulator (TI) and graphene. The realization of the great promises of the TI, however, requires the control of its defect states. In this talk, I will discuss how the intrinsic factors set the minimum defect density in pnictogen chalcogenides. To our surprise, defect physics of TI can be qualitatively different from that of ordinary semiconductor, as spin-orbit coupling in a TI can be so large to make an acceptor a donor. I will also discuss how to engineer Dirac cone at the Fermi level of strongly bound graphene on a SiC substrate. My emphasis will be on how to apply undergrad textbook knowledge to cutting-edge materials research, in particular, to uncover the physics underlying the transfer of Dirac dispersion between different electronic states.