Multiorbital Dirac superconductors and their realization of higher-order topology
Phys. Rev. B 113, 104503 – Published 4 March, 2026
DOI: https://doi.org/10.1103/xd9m-7yfh
Abstract
Topological nodal superconductors (SCs) have attracted considerable interest due to their gapless bulk excitations and exotic surface states. In this paper, by establishing a general framework of the effective theory for multiorbital SCs in the weak-pairing limit, we realize a class of three-dimensional time-reversal () invariant Dirac SCs, with their topologically protected gapless Dirac nodes being located at generic momenta. By introducing -breaking pairing perturbations, we demonstrate the existence of Majorana hinge modes in these Dirac SCs as evidence of their realization of higher-order topology. We also propose a kind of -breaking Dirac SCs, whose Dirac nodes possess nonzero even chiralities and so are characterized by surface Majorana arcs.