Density of states for dirty d-wave superconductors: A unified and dual approach for different types of disorder - art. no. 100503

A two-parameter field theoretical representation is given of a two-dimensio nal dirty d-wave superconductor that interpolates between the Gaussian limi t of uncorrelated weak disorder and the unitary limit of a dilute concentra tion of resonant scatterers. It is argued that a duality holds between thes e two regimes from which follows that a linearly vanishing density of state s in the Gaussian limit transforms into a diverging one in the unitary limi t arbitrarily close to the Fermi energy.