Slave-Boson Mean-Field Theory of the Antiferromagnetic State in the Doubly Degenerate Hubbard Model - the Half-Filled Case -

Abstract

The antiferromagnetic ground state of the half-filled Hubbard model with the doubly degenerate orbital has been studied by using the slave-boson mean-field theory which was previously proposed by the present author. Numerical calculations for the simple cubic model have shown that the metal-insulator transition does not take place except at the vanishing interaction point, in strong contrast with its paramagnetic solution. The energy gap in the density of states of the antiferromagnetic insulator is much reduced by the effect of electron correlation. The exchange interaction $J$ plays an important role in the antiferromagnetism: although for $J=0$ the sublattice magnetic moment $m$ in our theory is fairly smaller than $m_{HFA}$ obtained in the Hartree-Fock approximation, $m$ for $J/U>0.2$ ($U$: the Coulomb interaction) is increased to become comparable to $m_{HFA}$. Surprisingly, the antiferromagnetic state is easily destroyed if a small, negative exchange interaction ($J/U<-0.05$) is introduced.

Latex 18 pages, 12 figures available on request to [email protected] Note: published in Phys. Rev. B with some minor modifications

Cited by in corpus (19)

• Slave-rotor mean field theories of strongly correlated systems and the Mott transition in finite dimensions
• Multi-band Gutzwiller wave functions for general on-site interactions
• Landau-Gutzwiller quasi-particles
• A Simple Treatment of Metal-Insulator Transition: Effects of Degeneracy, Temperature and Applied Magnetic Field
• Slave-boson approach to the metallic stripe phases with large unit cells
• Gutzwiller-correlated wave functions for degenerate bands: exact results in infinite dimensions
• Strongly renormalized quasi-two-dimensional electron gas in a heterostructure with correlation effects
• Slave bosons in radial gauge: a bridge between path integral and hamiltonian language
• Metal-insulator transition in a doubly orbitally degenerate model with correlated hopping
• Interpolative Approach for Solving the Anderson Impurity Model
• Effect of Hund's exchange on the spectral function of a triply orbital degenerate correlated metal
• Competition of crystal field splitting and Hund's rule coupling in two-orbital magnetic metal-insulator transitions
• The Metal-Insulator Transition in the Doubly Degenerate Hubbard Model
• Numerical Study for the Ground State of Multi-Orbital Hubbard Models
• Slave-spin mean field for broken-symmetry states: Néel antiferromagnetism and its phase separation in multi-orbital Hubbard models
• Mott and Wigner-Mott transitions in doped correlated electron systems: effects of superlattice potential and inter-site correlation
• Exact results in a slave boson saddle point approach for a strongly correlated electron model
• A Bespoke Single-Band Hubbard Model Material
• Band crossover and magnetic phase diagram of high-Tc superconducting compound Ba2CuO4-δ