Time-reversal-invariant topological superconductors and superfluids in two and three dimensions

Phys Rev Lett. 2009 May 8;102(18):187001. doi: 10.1103/PhysRevLett.102.187001. Epub 2009 May 4.

Abstract

We construct time-reversal invariant topological superconductors and superfluids in two and three dimensions. These states have a full pairing gap in the bulk, gapless counterpropagating Majorana states at the boundary, and a pair of Majorana zero modes associated with each vortex. The superfluid 3He B phase provides a physical realization of the topological superfluidity, with experimentally measurable surface states protected by the time-reversal symmetry. We show that the time-reversal symmetry naturally emerges as a supersymmetry, which changes the parity of the fermion number associated with each time-reversal invariant vortex and connects each vortex with its superpartner.