  We present a quantum transport theory for hybrid superconducting systems
based on our exact master equation approach. The total transient transport
current is decomposed into components that describe coherent transports through
different paths of particle and hole channels. We show that the coherent
transports are resultant interferences of numerous repeated tunneling processes
and cannot be rendered as a simple normal transmission or Andreev reflection as
usually described quantum transport involving superconductivity. As a practical
application, we find that the coherent transport currents passing through a
pair of well-separated Majorana zero modes vanish due to the totally
destructive interference between the particle and hole channels.
