Spin-polarized Majorana Bound States inside a Vortex Core in Topological Superconductors

Abstract

We reveal that Majorana bound states inside the vortex core in an odd-parity topological superconductivity classified as "pseudo-scalar" type in the gap function are distinctly spin-polarized by solving the massive Dirac Bogoliubov-de Gennes (BdG) equation considering the spin-orbit coupling. This result is universal for "Dirac superconductivity" whose rotational degree of freedom is characterized by the total angular momentum J = S + L and in marked contrast to the spin-degeneracy of the core bound states as the consequence of the conventional BdG equation. The spin-polarized vortex core can be easily detected by spin-sensitive probes such as the neutron scattering and other measurements well above the first critical magnetic field H_{c1}.