Condensed Matter Seminar

Dr. Liang Fu
Harvard University

Thursday, November 5, 2009
1:00 pm in SPL 52

Topological Insulators and Majorana Fermions

Abstract: Topological insulators are new classes of time-reversal-invariant insulators which have topologically protected gapless surface states.

We outline theory of topological insulators with an emphasis on bulk-boundary correspondence, as well as theoretical prediction of this new phase in real materials. We discuss recent experimental observations of Dirac-like surface states that establish topological insulator phase in a number of materials.

We next show theoretically that under appropriate conditions, a surface Dirac electron can fractionalize into two constituent Majorana fermions, which are long-sought---but never detected---elementary excitations.

Finally we propose schemes of detecting the existence of Majorana fermions on topological insulators and their striking properties such as non-locality and non-Abelian statistics.