2001/03/31 by M. Matsumoto, Masashige Matsumoto, Mikito Koga
Physics and Astronomy · #Advanced Condensed Matter Physics #Physics of Superconductivity and Magnetism #Rare-earth and actinide compounds #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevb.65.024508
10 pages, 5 figures, revtex, to be published in Phys. Rev. B
arxiv created 2001/09/25 · openalex publication_date 2001/12/17 · arxiv updated 2009/11/30 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A type of Kondo effect peculiar to unconventional superconductors is studied theoretically by using Wilson's numerical renormalization group method. In this case, the angular momentum of a Cooper pair plays an important role in the Kondo effect. It produces multichannel exchange couplings with a local spin. Here we focus on a px+ipy-wave state which is a full-gap system. The calculated impurity susceptibility shows that the local spin is almost quenched by the Kondo effect in the strong-coupling region (TK/\ensuremathΔ\ensuremath→\ensuremath∞), while the ground state is always a spin doublet over all the TK/\ensuremathΔ region. Here TK and \ensuremathΔ are the Kondo temperature and the superconducting energy gap, respectively. This is different from the s-wave pairing case where the Kondo singlet is realized for large TK/\ensuremathΔ values. The strong-coupling analysis shows that the px+ipy-wave Cooper pair is connected to the Kondo singlet via the orbital dynamics of the paired electrons, generating the spin of the ground state. This type of Kondo effect reflects the symmetry of the conduction electron system.