Andreev bound states in the Kondo quantum dots coupled to superconducting leads

Abstract

We have studied the Kondo quantum dot coupled to two superconducting leads and investigated the subgap Andreev states using the NRG method. Contrary to the recent NCA results ( Clerk and Ambegaokar 2000 Phys. Rev. B 61 9109; Sellier et al 2005 Phys. Rev. B 72 174502), we observe Andreev states both below and above the Fermi level.