Doctor of Philosophy
School of Physics
Xiang, Feixiang, Quantum Transport on Topological Matter, Doctor of Philosophy thesis, School of Physics, University of Wollongong, 2017. http://ro.uow.edu.au/theses1/139
Topological matter is a new state of matter which is characterized by topological nontrivial electronic structure. It not only has fundamental physical importance but also has practical applications. In this thesis, quantum transport measurement is used to study electronic structure and transport properties of various topological matter.
In Chapter 3, we report a magneto-transport study on single crystals of the topological insulator BiSbTe3. Besides Shubnikov-de Haas oscillations and weak anti-localization (WAL) from the topological surface state, we also observed a crossover from the weak anti-localization to weak localization (WL) with increasing magnetic field, which is temperature dependent and exhibits two-dimensional features. The crossover is proposed to be the transport manifestation of the coexistence of the topological surface state and two-dimensional electron gas on the surface of TIs.
In Chapter 4, we use Shubnikov-de Haas oscillations to investigate the electronic structure of the bulk conduction band of BiTeCl single crystals with different carrier densities. We observe the topological transition of the Fermi surface (FS) from a spindle-torus to a torus. The Landau level fan diagram reveals the expected non-trivial π Berry phase for both the inner and outer FSs. Angle-dependent oscillation measurements reveal threedimensional FS topology when the Fermi level lies in the vicinity of the Dirac point. All the observations are consistent with large Rashba spin-orbit splitting in the bulk conduction band...