Topological superconductors with spin-triplet pairings and Majorana Fermi arcs

We construct a three-dimensional topological superconductor Bogoliubov–de Gennes (BdG) Hamiltonian with the normal state being a three-dimensional topological insulator. By introducing inter-orbital spin-triplet pairings term Δ₃, there are topological Majorana nodes in the bulk and they are connected by Majorana Fermi arcs on the surface, similar to the case of Weyl semimetal. Furthermore, by adding an inversion-breaking term to the normal state, momentum-independent pairing terms with different parities can coexist in the BdG Hamiltonian, which creates more Majorana modes similar to Andreev bound states and a richer phase diagram.