We study several effects which lead to symmetry-broken momentum distributions of quantum gases released from optical lattices. In particular, we demonstrate that interaction within the first milliseconds of the time-of-flight expansion can strongly alter the measurement of the initial atomic...

We found a superfluid which spontaneously breaks the time-reversal symmetry in one-dimensional optical lattices. This twisted superfluid is characterized by an exponentially closing energy gap and long-range correlations. The quantum phase transition to the twisted superfluid phase is driven by...