A new possible transition from two- to one-channel Kondo physics in mesoscopic transport

Abstract

We study the joint effects of the Coulombic dot–lead interaction and intralead electron interaction on nonequilibrium transport through a quantum dot coupled to Luttinger liquid leads in the Kondo regime. By applying the nonperturbative canonical transformation technique and extended equation of motion method of nonequilibrium Green function approach, we find two types of zero-bias anomalies with an enhanced conductance for the renormalized exponent Y<1 and a suppressed conductance for Y>1. The transition between the two behaviors is found at Y≈1. For Y>1 and Y<1, tunneling between the dot and Luttinger liquid leads is suppressed and enhanced, respectively, and they reflect two different types of exciton-assist tunneling. These physics phenomena provide opportunities to easily study the transition of two-channel Kondo physics in the future experiments.