Nonlinear Conductance for the Two Channel Anderson Model

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.