Reentrance and Magnetic-Field-Induced Superconductivity with Kondo   Impurities: Bulk and Proximity Systems
  Reentrant behavior is known to exist and magnetic-field-induced superconductivity has been predicted in superconductors with Kondo impurities. We present a simple framework for understanding these phenomena and generalize it to explain the long-standing puzzle of paramagnetic reentrance in thick proximity systems as due to small amounts of Kondo impurities. 
Yuval B. Simons, Ora Entin-Wohlman, Yuval Oreg, and Yoseph Imry
cond-mat.supr-con