  We study theoretically how multiple scattering of light in a disordered
medium can spontaneously generate quantum correlations. In particular we focus
on the case where the input state is Gaussian and characterize the correlations
between two arbitrary output modes. As there is not a single all-inclusive
measure of correlation, we characterise the output correlations with three
measures: intensity fluctuations, entanglement, and quantum discord. We found
that, while a single mode coherent state input can not produce quantum
correlations, any other Gaussian input will produce them in one form or
another. This includes input states that are usually regarded as more classical
than coherent ones, such as thermal states, which will produce a non zero
quantum discord.
