Superconductivity in spin glass

A theory of superconductivity of disordered magnetic systems in the spin glass phase is developed on the basis of the $s-d$ exchange model of metals. The phase diagram of the temperature against the concentration of the magnetic admixture is constructed, and it is shown that the region of coexistence of superconductivity and the magnetic spin-glass phase depends critically on the exchange interaction parameter. At small values of this parameter, the spin-glass phase suppresses the superconductivity to a lesser extent than the paramagnetic phase does. At larger values of the parameter, at low temperatures, there can at the same concentration of the magnetic admixture be two critical temperatures of transition of the system to the superconducting state.