Two-dimensional Anderson-Hubbard model in DMFT+Sigma approximation

Abstract

Density of states, dynamic (optical) conductivity and phase diagram of paramagnetic two-dimensional Anderson-Hubbard model with strong correlations and disorder are analyzed within the generalized dynamical mean-field theory (DMFT+Sigma approximation). Strong correlations are accounted by DMFT, while disorder is taken into account via the appropriate generalization of the self-consistent theory of localization. We consider the two-dimensional system with the rectangular "bare" density of states (DOS). The DMFT effective single impurity problem is solved by numerical renormalization group (NRG). Phases of "correlated metal", Mott insulator and correlated Anderson insulator are identified from the evolution of density of states, optical conductivity and localization length, demonstrating both Mott-Hubbard and Anderson metal-insulator transitions in two-dimensional systems of the finite size, allowing us to construct the complete zero-temperature phase diagram of paramagnetic Anderson-Hubbard model. Localization length in our approximation is practically independent of the strength of Hubbard correlations. However, the divergence of localization length in finite size two-dimensional system at small disorder signifies the existence of an effective Anderson transition.

10 pages, 10 figures, improve phase diagram

References in corpus (3)

• Metal-insulator transition in two-dimensional electron systems
• Pseudogaps in Strongly Correlated Metals: Optical Conductivity within the Generalized Dynamical Mean-Field Theory Approach
• Self-consistent study of Anderson localization in the Anderson-Hubbard model in two and three dimensions

Cited by in corpus (10)

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• Generalized dynamical mean-field theory in physics of strongly correlated systems
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• Nonequilibrium DMFT+CPA for Correlated Disordered Systems
• Disorder Effects in BCS-BEC Crossover Region of Attractive Hubbard Model
• Attractive Hubbard Model: Homogeneous Ginzburg - Landau Expansion and Disorder
• DMFT+Sigma approach to disordered Hubbard model
• Ginzburg - Landau Expansion in BCS - BEC Crossover Region of Disordered Attractive Hubbard Model
• Disorder Enhanced Thermalization in Interacting Many-Particle System