Realization of Topological Behavior in Sn-based Materials
Topological insulators (TIs), bulk insulators with symmetry-protected surface and edge states that exhibit unique spin and conductivity properties, have potential applications in future electronic devices. TIs of the (Bi,Sb)2(Te,Se)3 family have been extensively studied, and there has been recent interest in Sn-based TIs. Our group has focused on the experimental realization of two Sn-based TIs: stanene, a two-dimensional monolayer of Sn similar to graphene, and SnTe, a three-dimensional crystal whose topological states are protected by crystalline symmetry. For both materials, structure plays an important role in their topological properties. In this talk I will discuss the growth of monolayer stanene on Bi2Te3 and the use of synchrotron x-ray diffraction to distinguish between the planar and buckled polymorphs of monolayer Sn. I will also show how the topological surface states of thin film SnTe can be protected at the interface between SnTe and SrTiO3. This strategy for using topological surface states in a device avoids contamination by air exposure and avoids Fermi level pinning observed for bare SnTe surfaces.
|Realization of Topological Behavior in Sn-based Materials|
Wednesday, April 19, 2017, 11 a.m.–noon PT
Los Angeles, CA, United States