Recently the superconductor and topological semimetal PbTaSe2 was experimentally found to exhibit surface-only lattice rotational symmetry breaking below Tc. We exploit the Ginzburg-Landau free energy and propose a microscopic two-channel model to study possible superconducting states on the surface of PbTaSe2. We identify two types of topological superconducting states. One is time-reversal invariant and preserves the lattice hexagonal symmetry while the other breaks both symmetries. We find that such time-reversal symmetry breaking is unavoidable for a superconducting state in a two dimensional irreducible representation of crystal point group in a system where the spatial inversion symmetry is broken and the strong spin-orbit coupling is present. Our findings will guide the search for topological chiral superconductors.
@article{arxiv.1905.11584,
title = {Topological Superconductivity Intertwined with Broken Symmetries},
author = {Hui-Ke Jin and Dong-Hui Xu and Yi Zhou},
journal= {arXiv preprint arXiv:1905.11584},
year = {2019}
}