Related papers: Hole-Density Evolution of the One-Particle Spectra…
Quantum Monte Carlo (QMC) and Maximum Entropy (ME) techniques are used to study the spectral function $A({\bf p},\omega)$ of the one band Hubbard model in strong coupling including a next-nearest-neighbor electronic hopping with amplitude…
The internal structure of doped holes in the Mott insulator may provide important insight into the physics of doped cuprates. Its observability via a single-particle probe by scanning tunneling spectroscopy (STS) and angle-resolved…
The 2D t-J model with and without t' and t'' hopping-terms is studied by exact diagonalization on a 5 x 4 cluster, which realizes a hole stripe in y-direction in a dimerized singlet background. Next nearest hopping terms with a sign…
Several experiments in the context of ladder materials have recently shown that the study of simple models of anisotropic ladders (i.e. with different couplings along legs and rungs) is important for the understanding of these compounds. In…
We study the hole and magnon spectral functions as a function of hole doping in the two-dimensional (2D) t-J and t-t'-t"-J models working within the limits of the spin-wave theory, by linearizing the hole-spin-deviation interaction and by…
Using numerical techniques we study the spectral function $A(k,\omega)$ of a spin-fermion model for cuprates in the regime where magnetic and charge domains (stripes) are developed upon hole-doping. From $A(k,\omega)$ we study the…
We study the spectral function of two-leg Hubbard ladders with the time-dependent density matrix renormalization group method (tDMRG). The high-resolution spectrum displays features of spin-charge separation and a scattering continuum of…
Exact diagonalization studies for a doped t-J ladder (or double chain) show hole pairing in the ground state. The excitation spectrum separates into a limited number of quasiparticles which carry charge $+|e|$ and spin ${1 \over 2}$ and a…
Within the t-t'-J model, the asymmetry of the electron spectrum and quasiparticle dispersion in hole-doped and electron-doped cuprates is discussed. It is shown that the quasiparticle dispersions of both hole-doped and electron-doped…
We study the single-particle properties of quarter-filled ladder systems such as sodium vanadate by means of a recently developed generalization of the variational cluster perturbation theory to extended Hubbard models. We find a…
In the framework of the planar t-J model for cuprates we analyze the development of a pseudo gap in the density of states, which at low doping starts to emerge for temperatures T<J and persists up to the optimum doping. The analysis is…
A theory of angle-resolved photoemission (ARPES) in doped cuprates and other charge-transfer Mott insulators is developed taking into account the realistic (LDA+U) band structure, (bi)polaron formation due to the strong electron-phonon…
A finite size scaling analysis of the spectral function and of the optical conductivity of a single hole moving in an antiferromagnetic background is performed. It is shown that both the low energy quasiparticle peak and the broad higher…
Clusters of the two-dimensionnal t--J model with 2 holes and up to 26 sites are diagonalized using a Lanczos algorithm. The behaviour of the binding energy with system size suggests the existence of a finite critical value of J above which…
We have carried out density-matrix-renormalization group (DMRG) calculations for the problem of one doped hole in a two-leg $t-J$ ladder. Recent studies have concluded that exotic "Mott" physics --- arising from the projection onto the…
The quasiparticle dispersion in the one-hole t-t'-t"-J model is studied. Both the finite-size diagonalization and the self-consistent Born approximation calculations have been performed and compared. The quasiparticle band structures in the…
We present an exact diagonalization study of the single particle spectral function in the so-called t-t'-t''-J model in 2D. As a key result, we find that unlike the `pure' t-J model, hole doping leads to a major reconstruction of the…
This work investigates a d-p Hubbard model by the n-pole approximation in the hole-doped regime. In particular, the spectral function $A(\omega,\vec{k})$ is analyzed varying the filling, the local Coulomb interaction and the $d-p$…
The recent angle-resolved photoemission measurements performed up to binding energies of the order of 1eV reveals a very robust feature: the nodal quasi-particle dispersion breaks up around 0.3-0.4eV and reappears around 0.6-0.8eV. The…
Using the Ogata-Shiba wave function, the spectral functions of the one-dimensional infinite U Hubbard model are calculated for various concentrations. It is shown that the ``shadow band'' feature due to 2k_F fluctuations becomes more…