Temperature-dependent spectral function of a Kondo impurity in an s-wave superconductor

Article

关键词: NUMERICAL RENORMALIZATION-GROUP;    MAGNETIC-IMPURITIES;    ALLOYS;    STATES;   

DOI  :  10.1103/PhysRevB.99.174502

来源: SCIE

【 摘 要 】

Using the numerical renormalization group method, the effect due to a Kondo impurity in an s-wave superconductor is examined at finite temperature T. The T behaviors of the spectral function and the magnetic moment at the impurity site are calculated. At T = 0, the spin due to the impurity is in a singlet state when the ratio between the Kondo temperature T-k and the superconducting gap Delta(0) is larger than 0.26. Otherwise, the spin of the impurity is in a doublet state. We show that the separation of the double Yu-Shiba-Rusinov peaks in the spectral function shrinks as T increases if T-k/Delta(0) < 0.26, while it expands if T-k/Delta(0) > 0.26 and Delta(0) remains constant. These features could be measured by experiments and thus provide a unique way to determine whether the spin of the single Kondo impurity is in the singlet or doublet state at zero temperature.

【 授权许可】

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