Determining transport parameters for superconductor/normal metal point contacts at fixed temperature from conductance versus magnetic field data

Transport data for superconductor/normal metal point contacts often consists of normalized conductance versus applied voltage as a function of reduced temperature, from which the barrier parameter, Z, and the broadening parameter, Γ, for the contact can be determined, in addition to other features of interest. We present a new strategy for determining these parameters, namely from normalized conductance as a function of applied magnetic field at fixed temperature, even when conductance versus variable temperature data is absent. This analysis technique will be demonstrated for several point contacts, over a wide range of parameter values.

Research highlights
► We present a new strategy for determining the point contact parameters Z and Γ.
► We analyze conductance as a function of applied magnetic field at fixed temperature.
► We extend the linear two channel model to have a polynomial form in applied field.
► A single (Z, Γ) pair fits the entire point contact data set.