Superconducting Instability in the Periodic Anderson Model
  Employing a quantum Monte Carlo simulation we find a pairing instability in the normal state of the infinite dimensional periodic Anderson model. Superconductivity arises from a normal state in which the screening is protracted and which is clearly not a Fermi liquid. The phase diagram is reentrant reflecting competition between superconductivity and Fermi liquid formation. The estimated superconducting order parameter is even, but has nodes as a function of frequency. This opens the possibility of a temporal node and an effective order parameter composed of charge pairs and spin excitations. 
A. N. Tahvildar-Zadeh, M. H. Hettler, M. Jarrell (Department of   Physics, University of Cincinnati, Cincinnati)