Magnetic properties and temperature variation of spectra in the Hubbard model

Abstract

Using the strong coupling diagram technique, magnetic and spectral properties of the two-dimensional repulsive Hubbard model are investigated in the ranges of repulsions $t\le U\le 10t$, temperatures $0.1t\lesssim T\lesssim 4t$ and electron concentrations $0.6\lesssim \bar{n}\le 1$ with $t$ the hopping constant. The approach takes into account interactions of electrons with spin and charge fluctuations of all ranges and fulfils the Mermin-Wagner theorem. Temperature and concentration dependencies of the uniform magnetic susceptibility, the variation of the double occupancy with the repulsion and the temperature dependence of the square of the site spin are in satisfactory agreement with Monte Carlo results. Three types of the temperature variation of the electron energy spectrum can be distinguished at half-filling. For $U\lesssim 3t$, at low temperatures, there are two nonintersecting bands, which approach each other on the boundary of the magnetic Brillouin zone. With increasing $T$ these bands merge into one band crossing the Fermi level. For $4t\lesssim U\lesssim 6t$, the low-temperature picture described above is supplemented with a low-intensity spin-polaron band located near the Fermi level. As its counterpart in the strong-correlation case, the band is formed by bound states of electrons and spin excitations. However, in contrast to the former case, the band exists even at half-filling and occupies the entire Brillouin zone. As for lower $U$, with increasing temperature, all bands coalesce into a single band. For $U\gtrsim 7t$ and low temperatures the spectrum has a pronounced four-band structure, which with increasing $T$ transforms into two Hubbard subbands.

arXiv comment12 pages, 14 figures

References in corpus (39)

• Angle-resolved photoemission spectroscopy of the cuprate superconductors
• Quantum Cluster Theories
• Diagrammatic routes to nonlocal correlations beyond dynamical mean field theory
• The spectral weight of the Hubbard model through cluster perturbation theory
• Dynamical vertex approximation - a step beyond dynamical mean field theory
• Non-perturbative many-body approach to the Hubbard model and single-particle pseudogap
• Variational cluster approach to correlated electron systems in low dimensions
• Cluster Dynamical Mean Field Theory of the Mott Transition
• Hot Spots and Pseudogaps for Hole- and Electron-Doped High-Temperature Superconductors
• 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
• Quantum Monte Carlo study of the two-dimensional fermion Hubbard Model
• High-energy kink in high-temperature superconductors
• Comparing pertinent effects of antiferromagnetic fluctuations in the two and three dimensional Hubbard model
• Anomalous low doping phase of the Hubbard model
• Fermions in 2D Optical Lattices: Temperature and Entropy Scales for Observing Antiferromagnetism and Superfluidity
• Efficient perturbation theory for quantum lattice models
• Anomalous high energy dispersion in photoemission spectra from insulating cuprates
• Absence of a Slater Transition in The Two-Dimensional Hubbard Model
• A Short Introduction to Numerical Linked-Cluster Expansions
• Strong-Coupling Perturbation Theory of the Hubbard Model
• Thermodynamics of strongly interacting fermions in two-dimensional optical lattices
• First order Mott transition at zero temperature in two dimensions: Variational plaquette study
• Impact of nonlocal correlations over different energy scales: A Dynamical Vertex Approximation study
• Mott Transition in the Two-Dimensional Hubbard Model
• Antiferromagnetic correlations in two-dimensional fermionic Mott-insulating and metallic phases
• Thermodynamics of the planar Hubbard model
• Phase diagram and single-particle spectrum of CuO${}_2$ layers within a variational cluster approach to the 3-band Hubbard model
• Pseudogap and singlet formation in cuprate and organic superconductors
• Precursors of the insulating state in the square lattice Hubbard model
• One-loop approximation for the Hubbard model
• Lattice susceptibility for 2D Hubbard Model within dual fermion method
• 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
• The Mott transition in the strong coupling perturbation theory
• Exact Diagonalization Study of 2D Hubbard Model on Honeycomb Lattice: Semi-metal-Insulator Transition
• Continuum of many-particle states near the metal-insulator transition in the Hubbard model
• A CDMFT study of antiferromagnetic transition in the square-lattice Hubbard model: optical conductivity and electronic structure

Cited by in corpus (9)

• Hubbard-Kanamori model: spectral functions, negative electron compressibility, and susceptibilities
• Negative electron compressibility in the Hubbard Model
• Spin and charge fluctuations in the two-band Hubbard model
• Absence of superconductivity in the two-dimensional Hubbard model
• Two-dimensional extended Hubbard model at half-filling
• Phonon-assisted phase separation in strongly correlated systems
• Phase separation and pairing fluctuations in oxide materials
• Magnetic properties and superconductivity in the two-dimensional repulsive Hubbard model
• Hubbard model on a triangular lattice at finite temperatures