  Off-resonance conductance through weakly coupled quantum dots ("valley
conductance") is governed by cotunneling processes in which a large number of
dot states participate. Virtually the same states participate in the transport
at consecutive valleys, which leads to significant valley-valley conductance
correlations. These correlations are calculated within the constant interaction
model. Comparison with experiment shows that these correlations are less robust
in reality. Among the possible reasons for this is the breakdown of the
constant interaction model, accompanied by "scrambling" of the dot as the
particle number is varied.
