  A superconductor with interacting paramagnetic impurities is considered. The
impurities are coupled via the Ruderman-Kittel-Kasuya-Yoshida interaction. At a
temperature Tg, the system of magnetic impurities forms a spin-glass state. We
study the effect of the spin-spin interactions on the superconducting
transition point at T<Tg. We show that superconducting properties depend on the
state of the spin system via spin-spin autocorrelation functions. With the help
of the Keldysh technique, a general nonequilibrium Gor'kov equation is derived.
Possible ageing effects in the superconducting transition point are discussed.
The equilibrium superconducting transition point is found explicitly and shown
to be shifted towards higher temperatures and impurity concentrations compared
to the classical Abrikosov-Gor'kov's curve. The corresponding shift of the
superconducting quantum critical point is quite small (about 10%). A method of
calculating spin-spin correlation function is suggested. The method combines
the ideas of random mean-field method and virial expansion. We calculate
analytically the first virial term for the spin-spin correlator for the quantum
Heisenberg spin glass with the RKKY interactions in the quasiequilibrium
regime.
