Effects of nonmagnetic impurities on spinfluctuations induced superconductivity.pdfVIP

Effects of non-magnetic impurities on spin-fluctuations induced superconductivity S. Dusuel Institut f¨ur Theoretische Physik, Universit¨at zu K¨oln, Z¨ulpicher Str. 77, D-50937 K¨oln, Germany D. Zanchi ´ Laboratoire de Physique Th´eorique et Hautes Energies, 2 Place Jussieu, 4 75252 Paris C´edex 05, France. 0 (Dated: February 2, 2008) 0 We study the effects of non-magnetic impurities on the phase diagram of a system of interacting 2 electrons with a flat Fermi surface. The one-loop Wilsonian renormalization group flow of the angle dependent diffusion function D(θ , θ , θ ) and interaction U (θ , θ , θ ) determines the critical tem- n 1 2 3 1 2 3 a perature and the nature of the low temperature state. As the imperfect nesting increases the critical J temperature decreases and the low temperature phase changes from the spin-density wave (SDW) 4 to the d-wave superconductivity (dSC) and finally, for bad nesting, to the random antiferromagnetic 1 state (RAF). Both SDW and dSC phases are affected by disorder. The pair breaking depends on the imperfect nesting and is the most efficient when the critical temperature for superconductivity ] is maximal. l e - PACS numbers