Nonlinear Conductance for the Two Channel Anderson Model

TL;DR

This paper uses the Noncrossing Approximation to compute the differential conductance of a two-channel Kondo impurity, aligning well with experimental data and supporting a new scaling hypothesis with finite temperature corrections.

Contribution

It introduces a detailed calculation of conductance in the two-channel Anderson model using integral equations, validating experimental observations and theoretical scaling.

Findings

Good agreement with Cu point contact experiments

Finite temperature corrections to scaling observed

Asymmetric conductance predicted for unequal couplings

Abstract

Using the integral equations of the Noncrossing Approximation, the differential conductance is computed as a function of voltage for scattering from a two channel Kondo impurity in a point contact. The results compare well to experimental data on Cu point contacts by Ralph and Buhrman. They support a recently proposed scaling hypothesis, and also show finite temperature corrections to scaling in agreement with experiment. The conductance signal is predicted to be asymmetric in the bias when the impurity is not equally coupled to left and right moving electrons.