  We investigate the quantum interference effects in two types of matter-wave
mixing experiments: one with initial matter waves prepared in independent Fock
states (type I) and the other with each individual particle prepared in a same
coherent superposition of states (type II). In the type I experiment, a
symmetric wavefunction of bosons leads to constructive quantum interference and
shows final state stimulation, while an anti-symmetric wavefunction of fermions
results in destructive quantum interference and inhibited matter wave mixing.
In the type II experiment, a coherent superposition state leads to constructive
quantum interference and enhanced matter wave mixing for both bosons and
fermions, independent of their quantum statistics.
