Condensed Matter Physics Seminar
University of Illinois at Urbana Champain
Insulating phases of matter with non-trivial topological properties have been shown to exist in strong magnetic fields and very low temperatures. Recently time reversal symmetric, insulating phases of matter were discovered which are identified by topological properties of their band structure and are distinguished from trivial insulating phases by the presence of robust chiral edge modes even at room temperature. Even though exotic properties of the edge modes in these topological insulators, seem to be dependent on the bulk to be insulator, in this talk I show that some of the edge properties, which can have interesting applications for thermoelectric power generation and quantum computing, are intact even when the bulk is metallic. These results are specially important since the undoped compounds with the topological band structure are not usually insulating. At the end I show how application of strain can also push graphene into such topological insulating phase and more interestingly can realize phases with fractional excitations without breaking the time reversal symmetry.