The T = 0 spin stiffness ρs and the transverse susceptibility χ⊥ of the square lattice half-filled Hubbard model are calculated as a function of the Hubbard parameter ratio U/t by series expansions around the Ising limit. We find that the calculated spin-stiffness, transverse susceptibility, and sublattice magnetization for the Hubbard model smoothly approach the Heisenberg values for large U/t...

We present a method for the calculation of few-electron spectral functions of the one-dimensional Hubbard model which relies on a pseudofermion description introduced recently in Ref. [6]. The spectral functions are expressed as a convolution of pseudofermion dynamical correlation functions. Our general method involves the direct evaluation of the matrix elements of pseudofermion operators betw...

A simple scheme, capable of treating transport in molecular junctions in the language of many-body states, is presented. By introducing an ansatz in Liouville space, similar to the generalized Kadanoff-Baym approximation, a quantum master equation QME -like expression is derived starting from the exact equation of motion for Hubbard operators. Using an effective Liouville space propagation, a d...

Motivated by the problem of N coupled Hubbard chains, we investigate a generalisation of the Schulz-Shastry model containing two species of one-dimensional fermions interacting via a gauge field that depends on the positions of all the particles of the other species. The exact many body ground state of the model can be easily obtained through a unitary transformation of the model. The correlati...

The equation for the charge vertex γ of the t−J model is derived and solved in leading order of an 1/N expansion, working directly in terms of Hubbard operators. Various quantities which depend crucially on γ are then calculated, such as the life time and the transport life time of electrons due to a charge coupling to other degrees of freedom and the charge-charge correlation function. Our res...

We propose here an alternative interpretation of the fermi-linarization approach to interacting electron systems, based on the requirement that the coefficients of the linearized operators are Clifford-like variables, whose anticommutator equals an unknown constant c. We apply the approximation to the Falicov-Kimball model, explicitly solving the self-consistency equation for the unknown, which...

We find the singular transformation between the electron operator and the pseu-doparticle operators for the Hubbard chain. We generalize the concept of quasiparti-cle to one-dimensional electronic systems which in 1D refers to many-pseudoparticle objects. We obtain explicit results for the electron renormalization factor, self energy, and vertex functions at the Fermi points. We also discuss th...

We explore the relationship between the SU(2) sector of a general integrable field theory and the all-loop guess for the anomalous dimensions of SU(2) operators in N = 4 super Yang-Mills theory. We demonstrate that the SU(2) structure of a nested Bethe ansatz alone reproduces much of the all-loop guess without depending on the details of the particular field theory. We speculate on the implicat...

LiV2O4, a frustrated mixed valent metal (d 1 ↔ d2), is argued to undergo two spinscreening processes. The first quenches the effective spin to produce the spin 1 2 behavior seen below room temperature[1] , while the second produces the heavy fermi liquid character seen at low temperatures[2]. We present here a preliminary discussion of a t-J model with strong Hund’s coupling of the strongly cor...

We calculate the one-particle density of states for the Mott–Hubbard insulating phase of the Hubbard model on a Bethe lattice in the limit of infinite coordination number. We employ the Kato–Takahashi perturbation theory around the strong-coupling limit to derive the Green function. We show that the Green function for the lower Hubbard band can be expressed in terms of polynomials in the bare h...