Auxiliary dynamical mean-field approach for the Anderson-Hubbard model with off-diagonal disorder
Phys. Rev. B 112, 085117 – Published 11 August, 2025
DOI: https://doi.org/10.1103/6dg8-5r1q
Abstract
This study reports a theoretical framework that combines the auxiliary coherent potential approximation with dynamical mean-field theory (ACPA-DMFT) to study strongly correlated and disordered electronic systems with both diagonal and off-diagonal disorders. In this method, by introducing an auxiliary coupling space with extended local degree of freedom, the diagonal and off-diagonal disorder are treated in a unified and self-consistent framework of coherent potential approximation, within which the dynamical mean-field theory is naturally combined to handle the strongly correlated Anderson-Hubbard model. Using this approach, we compute Matsubara Green's functions for a simple cubic lattice at finite temperature and derive impurity spectral functions through the maximum entropy method. Our results reveal the critical influence of off-diagonal disorder on Mott-type metal-insulator transitions. Specifically, a reentrant phenomenon is identified, wherein the system transitions between insulating and metallic states under varying interaction strengths. The ACPA-DMFT method provides an efficient and robust computational approach for exploring the intricate interplay between disorder and strong correlations.
