Theory of Knight Shift and Spin-Lattice Relaxation Rates of Pu-115

摘要

We calculated the Knight shift and spin-lattice relaxation rates of Pu-115 compounds assuming d-wavc superconductivity in the presence of strong impurity scattering. We discuss the implications for recent measurements of the spin-lattice relaxation rate in the Pu 115 compound PuRhGas by Sakai and coworkers [J. Phys. Soc. Jpn. 74, 1710 (2005)] and present a prediction for the corresponding Knight shift. In addition, we noticed a significant round-off of the spin-lattice relaxation rate 1/T_1 just above the superconducting tra.nsit.ion temperature that is not observed in the sister compound PuCoGa_5. It appears that in PuRhGa_5 superconductivity is mediated by spin fluctuations, too. This provides additional support to the scenario of superconducting pairing mediated by spin fluctuations in the Pu-115 compounds similar to the Ce-115 compounds and the high-temperature copper-oxide superconductors.