抄録
Various types of anisotropic superconductivity have been investigated near its transition temperature in the periodic Anderson Hamiltonian with a weak attractive interaction between the nearest neighbor f electrons. The superconductivity with the s-, p- or dγ-symmetry is possible in a model where the f sites form a simple cubic lattice. Due to the finite range of the interaction, even the s-symmetry Cooper pairs can be anisotropic. This anisotropic s-wave superconductivity has many different properties from the ordinary BCS superconductivity if the Fermi wave vector is large; the transition temperature Tc can be significantly reduced by nonmagnetic impurities, the specific heat jump can be smaller than the BCS value, and the energy gap near Tc can vanish along lines on the Fermi surface. The competition among different symmetries is discussed.
