Dirac and Weyl Superconductors in Three Dimensions

作者:Yang, Shengyuan A.*; Pan, Hui; Zhang, Fan
来源:Physical Review Letters, 2014, 113(4): 046401.
DOI:10.1103/PhysRevLett.113.046401

摘要

We introduce the concept of three-dimensional Dirac (Weyl) superconductors (SC), which have protected bulk fourfold (twofold) nodal points and surface Majorana arcs at zero energy. We provide a sufficient criterion for realizing them in centrosymmetric SCs with odd-parity pairing and mirror symmetry. Pairs of Dirac nodes appear in a mirror-invariant plane when the mirror winding number is nontrivial. Breaking mirror symmetry may gap Dirac nodes producing a topological SC. Each Dirac node evolves to a nodal ring when inversion-gauge symmetry is broken, whereas it splits into a pair of Weyl nodes when, and only when, time-reversal symmetry is broken.