  Electron gas in a wire connected to two terminals with potential drop is
studied with the Schwinger-Keldysh formalism. Recent studies, where the current
is enforced to flow with a Lagrange-multiplier term, demonstrated that the
current enhances the one-particle-correlation function. We report that in our
model, such enhancement is not guaranteed to occur, but conditional both on the
potential drop and the positions where we observe the correlation function.
That is, under a certain condition, spatially modulated pattern is formed in
the wire owing to the nonequilibrium current.
