  We present an analytical study of the loss of quantum coherence at absolute
zero. Our model consists of a harmonic oscillator coupled to an environment of
harmonic oscillators at absolute zero. We find that for an Ohmic bath, the
offdiagonal elements of the density matrix in the position representation decay
as a power law in time at late times. This slow loss of coherence in the
quantum domain is qualitatively different from the exponential decay observed
in studies of high temperature environments.
