  We study electric, thermal, and thermoelectric conductivities in the vicinity
of a z=2 superconductor-diffusive metal transition in two dimensions, both in
the high and low frequency limits. We find violation of the Wiedemann-Franz law
and a dc thermoelectric conductivity $\alpha$ that does not vanish at low
temperatures, in contrast to Fermi liquids. We introduce a Langevin equation
formalism to study critical dynamics over a broad region surrounding the
quantum critical point.
