  It is known that Manakov equation which describes wave propagation in two
mode optical fibers, photorefractive materials, etc. can admit solitons which
allow energy redistribution between the modes on collision that also leads to
logical computing. In this paper, we point out that Manakov system can admit
more general type of nondegenerate fundamental solitons corresponding to
different wave numbers, which undergo collisions without any energy
redistribution. The previously known class of solitons which allows energy
redistribution among the modes turns out to be a special case corresponding to
solitary waves with identical wave numbers in both the modes and travelling
with the same velocity. We trace out the reason behind such a possibility and
analyze the physical consequences.
