Lattice model of three-dimensional topological singlet superconductor with time-reversal symmetry

Understand

We study topological phases of time-reversal invariant singlet superconductors in three spatial dimensions.

• In these particle-hole symmetric systems the topological phases are characterized by an even-numbered winding number $\nu$.
• At a two-dimensional (2D) surface the topological properties of this quantum state manifest themselves through the presence of $\nu$ flavors of gapless Dirac fermion surface states, which are robust against localization from random impurities.
• We construct a tight-binding model on the diamond lattice that realizes a topologically nontrivial phase, in which the winding number takes the value $\nu =\pm 2$.