Tunable Majorana corner states in a two-dimensional second-order topological superconductor induced by magnetic fields

Starting from a minimal model of a time-reversal-invariant topological superconductor in two dimensions, the author shows that an in-plane magnetic field could drive the superconductor into a second-order topological phase, which features Majorana zero modes, bound at two of the four corners of the system. These Majorana corner states occur where edges with distinct topology intersect. Hence, the corner states are topologically protected. With variation of magnetic-field orientation, the nontrivial corner states would move along the boundary and reside on different corners.