While ordinary band insulators can also support conductive surface states, the surface states of topological insulators are distinct since they are symmetry protected through particle number conservation and time reversal symmetry. Topological insulators may provide new routes to search for exotic phenomena and particles, such as spin-polarized massless Dirac fermions or Marjorana fermions at topological insulator/superconductor interfaces, which may drive technological innovations such as spintronic devices and topological qubits for quantum computing. However, nontrivial surface states are difficult to separate experimentally from bulk impurity conduction in non-interacting TIs. In order to address these (and other) challenges, we are currently undertaking to study new families of possible topological insulators, including three-dimensional TIs, cubic Kondo insulators, and magnetically frustrated systems.
Topological States of Matter
A topological insulator is a time reversal symmetry preserving material with a non-trivial topological order, which behaves as an insulator in the bulk although its surface is conducting.