Dynamical mean-field theory of correlated hopping: A rigorous local approach

Abstract

A general approach for the description of correlated hopping in infinite dimensions, which is based on an expansion over electron hopping around the atomic limit, is developed. Such an approach keeps the dynamical mean-field theory local ideology and allows one to calculate the thermodynamical functions. A grand-canonical potential functional and a $\ensuremath{\Phi}$-derivable theory that does not introduce the self-energy is proposed. As limiting cases the Falicov-Kimball model with correlated hopping and the model with broken bonds (``diluted'' conductor) are investigated, and the connection with the Blackman-Esterling-Berk coherent potential approximation approach in the theory of the binary alloy with off-diagonal disorder is considered.