CPA theory for the giant Hall effect in disordered nanoscale systems

We present a theory based on the Green's-function formalism to study the so-called giant Hall effect in disordered nanoscale systems in which the metallic sites build up percolating networks. The disordered Green's functions are solved in the coherent potential approximation (CPA). This method is an extension of the Blackman-Esterling-Beck approach. The crucial point is that we are able to predict the quantum percolation threshold near which the Hall coefficient is enhanced by several orders of magnitude.