We study the properties of a quantum critical point which develops in a BCS
superconductor when pair-breaking suppresses the transition temperature to
zero. The pair fluctuations are characterized by a dynamical critical exponent
z=2. Except for very low temperatures, anomalous contribution to the
conductivity is proportional to the square root of T in three dimensions, but
to 1/T in two dimensions. At lowest temperatures, the conductivity correction
varies as T to the power 1/4 in three dimensions, and as ln(1/T) in two.Comment: 3 pages, 3 Postscript figures, Late
