Can electron pairing promote the Kondo state ?

Abstract: Usually a magnetism and superconductivity are regarded as competing phenomena. However, when the correlated quantum impurity (dot) is placed between a metallic and a superconducting reservoir the proximity-induced electron pairing can eventually promote the magnetic order, enhancing the Kondo temperature. We explain this counter-intuitive behaviour by the Schrieffer-Wolf approach and the numerical renormalization group calculations adopted to the Anderson impurity model. We argue that the Kondo resonance broadening is caused by the singlet-doublet phase transition.