English

Auxiliary dynamical mean-field approach for Anderson-Hubbard model with off-diagonal disorder

Strongly Correlated Electrons 2025-02-12 v1 Computational Physics Quantum Physics

Abstract

This work reports a theoretical framework that combines the auxiliary coherent potential approximation (ACPA-DMFT) with dynamical mean-field theory 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 disorders 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. By using this approach, we compute matsubara Green's functions for a simple cubic lattice at finite temperatures 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, where the system transitions between insulating and metallic states under varying interaction strengths. The ACPA-DMFT method provides an efficient and robust computational method for exploring the intricate interplay of disorder and strong correlations.

Keywords

Cite

@article{arxiv.2502.07353,
  title  = {Auxiliary dynamical mean-field approach for Anderson-Hubbard model with off-diagonal disorder},
  author = {Zelei Zhang and Jiawei Yan and Li Huang and Youqi Ke},
  journal= {arXiv preprint arXiv:2502.07353},
  year   = {2025}
}