Interference of Majorana fermions in NS junctions

We investigate interference of Majorana fermions (MFs) in NS junctions. A general formula of charge conductance G for NS junctions with two MFs is derived based on the low energy effective model. It is found that G for two MFs takes various values 0≤G≤4e2/h owing to interference of the MFs, while G is quantized as G=2e2/h for a single MF. The value of G is determined by symmetry of the system. As an example, we investigate the complete destructive interference of two degenerate MFs reported by Ii et al. [A. Ii, A. Yamakage, K. Yada, M. Sato, Y. Tanaka, Physical Review B 86 (2012) 174512.], and identify the symmetry responsible for the destructive interference.