  We study the effect of quantum fluctuations on the dynamics of a
quasi-one-dimensional Bose gas in an optical lattice at zero-temperature using
the truncated Wigner approximation with a variety of basis sets for the initial
fluctuation modes. The initial spatial distributions of the quantum
fluctuations are very different when using a limited number of plane-wave (PW),
simple-harmonic-oscillator (SHO) and self-consistently determined Bogoliubov
(SCB) modes. The short-time transport properties of the Bose gas, characterized
by the phase coherence in the PW basis are distinct from those gained using the
SHO and SCB basis. The calculations using the SCB modes predict greater phase
decoherence and stronger number fluctuations than the other choices.
Furthermore, we observe that the use of PW modes overestimates the extent to
which atoms are expelled from the core of the cloud, while the use of the other
modes only breaks the cloud structure slightly which is in agreement with the
experimental observations [1].
