Unidirectional Majorana Edge Mode in 2D Chiral Superconductor with Apllied Supercurrent

2D chiral superconductor is known to support chiral Majorana modes. Those modes are localized at the boundary and are gapless while the bulk remains fully gapped. In this report, I will show that by applying a supercurrent, a transition from gapped to gapless bulk states is possible. At the same time, the edge modes could survive the gap closing process and have the same chirality for opposite edges. Those modes are known as unidirectional Majorana modes. It could argue that those states are stable according to the theory of classification of Fermi surfaces.