Mitchell Institute for Fundamental Physics & Astronomy
College Station, Texas 77843
Spin-orbit coupling (SOC) is a relativistic interaction between a particle's spin and its motion. In most of the solid state physics textbooks, SOC is considered only a small perturbation to the electronic band structures of solid materials. The recent discovery of topological insulators, however, has manifested a key role of SOC in driving topologically non-trivial states. Since the interaction increases as the fourth power of the atomic number, topological electronic states are often realized in materials that are composed of heavy atoms.
In this talk, I will discuss our recent work on two classes of such “heavy materials”, namely metal chalcogenides and pyrochlore iridates that host exotic states driven by strong SOC. For the chalcogenides, I will present the controlled synthesis and growth mechanism of one-dimensional nanowires and their enhanced thermoelectric properties which may be associated with the non- trivial surface states. For the pyrochlore iridates, I will focus on the synthesis of bulk crystals and pulsed laser deposition of thin films. I will further discuss their unusual magnetic and electrical properties arising from the interplay of SOC, electron correlation, and geometrical frustration.