Kondo physics in the Josephon junction with DIII-class topological and s-wave superconductors

Abstract

We discuss the Kondo effect in the Josephson junction formed by the indirect coupling between a one-dimensional DIII-class topological and s-wave superconductors via a quantum dot. By performing the Schrieffer-Wolff transformation, we find that the single-electron occupation in the quantum dot induces various correlation modes, such as the Kondo and singlet-triplet correlations between the quantum dot and the s-wave superconductor and the spin-exchange correlation between the dot and Majorana doublet. Also, it modifies the Josephson effect by introducing the high-order anisotropic Kondo-like correlation and extra spin-exchange correlations. However, the Kondo temperature is still governed by the antiferromagnetic correlation between the dot and s-wave superconductor. We believe that this work shows the fundamental property of the DIII-class topological superconductor.