aqora

Channel-decomposed solution of the parquet equations in the two-dimensional Hubbard model

Christian Eckhardt, G. A. H. Schober, Carsten Honerkamp A

Bulletin of the American Physical SocietyMar 8, 20180 citations

Self-consistent solution of the Hubbard model on a 4x4 cluster with the parquet formalism

Herbert F. Fotso, Shuxiang Yang, Jun Liu +6 more

Bulletin of the American Physical SocietyMar 15, 20100 citations

t-Matrix Approximation to Two-Dimensional Hubbard Model

Hidetoshi Fukuyama, Yasumasa Hasegawa

Progress of Theoretical Physics SupplementJan 1, 199022 citations

Conserving approximations for strongly fluctuating electron systems. II. Numerical results and parquet extension

N. E. Bickers, Steven R. White

We describe an iterative technique for solution of the de Dominicis--Martin parquet equations for lattice electrons and state the relationship of this approach to conserving extensions of Hartree-Fock theory. We propose a physically motivated and computationally feasible pseudopotential approximation, which allows the solution of the parquet equations for the two-dimensional Hubbard model. We present calculations of static and dynamic Hubbard-model correlation functions based on the pseudopotential parquet and a simpler conserving approximation. For a wide parameter range the pseudopotential parquet results are in nearly quantitative agreement with finite-lattice quantum Monte Carlo results.We describe an iterative technique for solution of the de Dominicis--Martin parquet equations for lattice electrons and state the relationship of this approach to conserving extensions of Hartree-Fock theory. We propose a physically motivated and computationally feasible pseudopotential approximation, which allows the solution of the parquet equations for the two-dimensional Hubbard model. We present calculations of static and dynamic Hubbard-model correlation functions based on the pseudopotential parquet and a simpler conserving approximation. For a wide parameter range the pseudopotential parquet results are in nearly quantitative agreement with finite-lattice quantum Monte Carlo results.

Physical review. B, Condensed matterApr 1, 1991319 citations

Parquet approximation for molecules: Spectrum and optical conductivity of the Pariser-Parr-Pople model

Petra Pudleiner, Patrik Thunström, Angelo Valli +3 more

We study a simple model system for the conjugated $\ensuremath{\pi}$ bonds in benzene, the Pariser-Parr-Pople (PPP) model, within the parquet approximation (PA), exemplifying the prospects of the PA for molecules. Advantages of the PA are its polynomial scaling with the number of orbitals, and the natural calculation of one- and two-particle spectral functions as well as of response and correlation functions. We find large differences in the electronic correlations in the PPP model compared to a Hubbard model with only local interactions. The quasiparticle renormalization (or mass enhancement) is much weaker in the PPP than in the Hubbard model, but the static part of the self-energy enhances the band gap of the former. Furthermore, the vertex corrections to the optical conductivity are much more important in the PPP model. Because nonlocal interactions strongly alter the self-energy, we conclude that the PA is more suitable for calculating conjugated $\ensuremath{\pi}$ bonds in molecules than single site dynamical mean-field theory.We study a simple model system for the conjugated $\ensuremath{\pi}$ bonds in benzene, the Pariser-Parr-Pople (PPP) model, within the parquet approximation (PA), exemplifying the prospects of the PA for molecules. Advantages of the PA are its polynomial scaling with the number of orbitals, and the natural calculation of one- and two-particle spectral functions as well as of response and correlation functions. We find large differences in the electronic correlations in the PPP model compared to a Hubbard model with only local interactions. The quasiparticle renormalization (or mass enhancement) is much weaker in the PPP than in the Hubbard model, but the static part of the self-energy enhances the band gap of the former. Furthermore, the vertex corrections to the optical conductivity are much more important in the PPP model. Because nonlocal interactions strongly alter the self-energy, we conclude that the PA is more suitable for calculating conjugated $\ensuremath{\pi}$ bonds in molecules than single site dynamical mean-field theory.

arXiv:1812.04962Physical review. B./Physical review. BMar 11, 201923 citations

Dynamical vertex approximation for the two-dimensional Hubbard model

Thomas Schäfer, A. Toschi, Karsten Held

arXiv:1506.05706Journal of Magnetism and Magnetic MaterialsJul 30, 201540 citations

Parquet approximation calculation for the 2D Hubbard model

Related papers

Parquet approximation calculation for the 2D Hubbard model

Related papers