Non‐Centrosymmetric Superconductors on Honeycomb Lattice

Abstract

Non‐centrosymmetric topological superconductivity is studied in correlated doped quantum spin‐Hall insulators (QSHI) on honeycomb lattice without inversion symmetry where the intrinsic (Kane–Mele) and Rashba spin–orbit couplings can in general exist. The generic topologically non‐trivial superconducting phase diagram of the model system is explored. Over a certain parameter range, the parity‐mixing superconducting state with co‐existing spin‐singlet d + id and spin‐triplet p + ip‐wave pairing is found. On a zigzag nanoribbon, the parity‐mixing superconducting state shows co‐existing helical and chiral Majorana fermions at edges. The relevance of our results for experiments is discussed.