Related papers: Spectral Function of a $d-p$ Hubbard Model
We study single electron spectral functions in a quantum dimer model introduced by Punk, Allais and Sachdev (Ref. [1]). The Hilbert space of this model is spanned by hard-core coverings of the square lattice with two types of dimers:…
A simple approximation which captures some non-perturbative aspects of the one electron Green function of strongly interacting Fermion systems is developed. It provides a way to go one step beyond the usual dilute limit since…
Using the one-loop functional renormalization group technique we evaluate the self-energy in the weak-coupling regime of the 2D t-t' Hubbard model. At van Hove (vH) band fillings and at low temperatures the quasiparticle weight along the…
The regions of hole concentrations $0 \leq x \alt 0.3$ and temperatures $0.005|t| \leq T \leq 0.02|t|$ are studied in the t-J model of Cu-O planes of perovskite high-$T_c$ superconductors. For this purpose self-energy equations for hole and…
We evaluate the one-particle and double-occupied Green functions for the Hubbard model at half-filling using the moment approach of Nolting. Our starting point is a self-energy, $\Sigma(\vec{k},\omega)$, which has a single pole,…
We investigate the strong correlation effect in the spinless electron-hole two-band Hubbard model using the dynamical mean-field theory. At half filling, both the renormalization factor $Z$ and the number of conduction electrons (valence…
The two-orbital Hubbard-Kanamori model is studied using the strong coupling diagram technique. This approach allows one to take into account the interactions of electrons with spin, charge, and orbital fluctuations of all ranges. It was…
We present determinant quantum Monte Carlo simulations of the hole-doped single-band Hubbard-Holstein model on a square lattice, to investigate how quasiparticles emerge when doping a Mott insulator (MI) or a Peierls insulator (PI). The MI…
To clarify the origin of the pseudogap and strange metal states as well as their mutual relationship in cuprate superconductors, a comprehensive study on the spectral function, Fermi surface, resistivity and dynamical spin susceptivity of…
Since the discovery of half-filled cuprate to be a Mott insulator, the excitation spectra above the chemical potential for the unoccupied states has attracted many research attentions. There were many theoretical works using different…
Strong electron correlations lie at the origin of transformative phenomena such as colossal magneto-resistance and high-temperature superconductivity. Already near room temperature, doped copper oxide materials display remarkable features…
We present spectral and optical properties of the Hubbard model on a two-dimensional square lattice using a generalization of dynamical mean-field theory to magnetic states in finite dimension. The self-energy includes the effect of spin…
We investigate the low energy properties of a correlated metal in the proximity of a Mott insulator within the Hubbard model in two dimensions. We introduce a new version of the Cellular Dynamical Mean Field Theory using cumulants as the…
Equations for the electron Green's function of the two-dimensional Hubbard model, derived using the strong coupling diagram technique, are self-consistently solved for different electron concentrations $n$ and tight-binding dispersions.…
We have generalized the dynamical mean-field theory to study the doping dependence of the crossover from antiferromagnetic to short-range order modelled by an incommensurate spin density wave in the Hubbard model. The local selfenergy which…
The coexistence of $\pi$-flux state and d-wave RVB state is considered in this paper within the slave boson approach. A critical value of doping concentration $\delta_c$ is found, below which the coexisting $\pi$-flux and d-wave RVB state…
Using a recently developed perturbative approach, which considers Hubbard operators as fundamental excitations, we have performed electronic self-energy and spectral function calculations for the $t-J$ model on the square lattice. We have…
The electron Green's functions $G({\bf k},\omega)$ within the t-J model and in the regime of intermediate doping is studied analytically using equations of motion for projected fermionic operators and the decoupling of the self energy into…
We present a numerical study of the doping dependence of the spectral function of the n-type cuprates. Using a variational cluster-perturbation theory approach based upon the self-energy-functional theory, the spectral function of the…
Using the method which retains the rotation symmetry of spin components in the paramagnetic state and has no preset magnetic ordering, spectral and magnetic properties of the two-dimensional t-J model in the normal state are investigated…