Influence of spin and charge fluctuations on spectra of the two-dimensional Hubbard model

Abstract

The influence of spin and charge fluctuations on spectra of the two-dimensional fermionic Hubbard model is considered using the strong coupling diagram technique. Infinite sequences of diagrams containing ladder inserts, which describe the interaction of electrons with these fluctuations, are summed, and obtained equations are self-consistently solved for the ranges of Hubbard repulsions $2t\le U\le 10t$, temperatures $0.2t\lesssim T\lesssim t$ and electron concentrations $0.7\lesssim \bar{n}\le 1$ with $t$ the intersite hopping constant. For all considered $U$ the system exhibits a transition to the long-range antiferromagnetic order at $T_{\mathrm{AF}}\approx 0.2t$. At the same time no indication of charge ordering is observed. Obtained solutions agree satisfactorily with results of other approaches and obey moments sum rules. In the considered region of the $U$-$T$ plane, the curve separating metallic solutions passes from $U\approx 6t$ at the highest temperatures to $U=2t$ at $T\approx T_{\mathrm{AF}}$ for half-filling. If only short-range fluctuations are allowed for the remaining part of this region is occupied by insulating solutions. Taking into account long-range fluctuations leads to strengthening of maxima tails, which transform a part of insulating solutions into bad-metal states. For low $T$, obtained results allow us to trace the gradual transition from the regime of strong correlations with the pronounced four-band structure and well-defined Mott gap for $U\gtrsim 6t$ to the Slater regime of weak correlations with the spectral intensity having a dip along the boundary of the magnetic Brillouin zone due to an antiferromagnetic ordering for $U\lesssim 3t$. For $T\approx T_{\mathrm{AF}}$ and $U\gtrsim 7t$ doping leads to the occurrence of a pseudogap near the Fermi level, which is a consequence of the splitting out of a narrow band from a Hubbard subband.

15 pages, 14 figures

References in corpus (18)

• Diagrammatic routes to nonlocal correlations beyond dynamical mean field theory
• Dynamical vertex approximation - a step beyond dynamical mean field theory
• Variational cluster approach to correlated electron systems in low dimensions
• Cluster Dynamical Mean Field Theory of the Mott Transition
• A universal high energy anomaly in angle resolved photoemission spectra of high temperature superconductors - possible evidence of spinon and holon branches
• Fate of the false Mott-Hubbard transition in two dimensions
• High-energy kink in high-temperature superconductors
• Dual fermion approach to the two-dimensional Hubbard model: Antiferromagnetic fluctuations and Fermi arcs
• Anomalous high energy dispersion in photoemission spectra from insulating cuprates
• Asymmetry of the electronic states in hole- and electron-doped cuprates: Exact diagonalization study of the t-t'-t''-J model
• First order Mott transition at zero temperature in two dimensions: Variational plaquette study
• Mott Transition in the Two-Dimensional Hubbard Model
• Phase diagram and single-particle spectrum of CuO${}_2$ layers within a variational cluster approach to the 3-band Hubbard model
• Interplay Between $d$-wave Superconductivity and a Bond Density Wave in the one-band Hubbard model
• Fluctuating charge density waves in the Hubbard model
• Magnetic susceptibility of the two-dimensional Hubbard model using a power series for the hopping constant
• Properties of the half-filled Hubbard model investigated by the strong coupling diagram technique
• Continuum of many-particle states near the metal-insulator transition in the Hubbard model

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