Fumiaki Shibata

Self-Consistent Treatment of the Wolff-Moriya Model

The Wolff-Moriya model for the localized magnetic moments in metals is treated selfxad consistently by using the decoupling method of the double-time Green functions. The resultxad ing scattering matrix is solved exactly in the strongly correlated limit and is compared with solutions for the s-d exchange model and for the Anderson model. The expression for the resistivity differs qualitatively from those for the s-d exchange and Anderson models and can be associated with the anomaly observed in Rh-Fe alloy.

On the Origin of Resonance State in Superconductors

Effects of impurities on superconductivity have been investigated by many authors; of these works the resonance state in the BCS continuum is not so clarified yet. Though Shibal) obtained by using the model of classical spin the localized bound state in the superconducting energy gap, one finds no resonance state in the continuum at all. On the other hand, Fetter2> observed a resonance scattering near the Fermi surface by employing a delta-shell potential of the form CV(r) = (2ma)·tD(r-a)A, (1)