Dynamical mean-field theory of the Anderson-Hubbard model with local and nonlocal disorder in tensor formulation

To explore correlated electrons in the presence of local and nonlocal disorder, the Blackman-Esterling-Berk method for averaging over off-diagonal disorder is implemented into dynamical mean-field theory using tensor notation. The impurity model combining disorder and correlations is solved using the recently developed fork tensor-product state solver, which allows one to calculate the single particle spectral functions on the real-frequency axis. In the absence of off-diagonal hopping, we establish exact bounds of the spectral function of the noninteracting Bethe lattice with coordination number Z. In the presence of interaction, the Mott insulating paramagnetic phase of the one-band Hubbard model is computed at zero temperature in alloys with site- and off-diagonal disorder. When the Hubbard U parameter is increased, transitions from an alloy band insulator through a correlated metal into a Mott insulating phase are found to take place.

Automated summary

In order to explore correlated electrons in the presence of local and nonlocal disorder, the study combines the Blackman-Esterling-Berk method for averaging over off-diagonal disorder with dynamical mean-field theory using tensor notation. Through the newly developed fork tensor-product state solver, they were able to solve the impurity model combining disorder and correlations, allowing the calculation of single particle spectral functions on the real-frequency axis. The study also analyzes the transitions from an alloy band insulator through a correlated metal into a Mott insulating phase as the Hubbard U parameter is increased.