Related papers: Spectral functions, Fermi surface and pseudogap in…
We describe here a minimal theory of tight binding electrons moving on the square planar Cu lattice of the hole-doped cuprates and mixed quantum mechanically with pairs of them (Cooper pairs). Superconductivity occurring at the transition…
We demonstrate that many features ascribed to strong correlation effects in various spectroscopies of the cuprates are captured by a calculation of the self-energy incorporating effects of spin and charge fluctuations. The self energy is…
We introduce a new class of fractional backward orthogonal functions designed for the spectral approximation of weakly singular adjoint Volterra integral equations. These basis functions generate an approximation space that naturally…
We present a simple modification of the standard U(1) slave boson construction for the single band t-J model which accounts for two-particle bound states of spinons and holons. This construction naturally gives rise to fractionalized Fermi…
The spectral function of one hole in different magnetic states of the one-dimensional t-J model including three-site term and frustration $J^{\prime}$ is studied. In the strong coupling limit $J \to 0$ (corresponding to $U \to \infty$ of…
We reanalyse the mathematical formulation of the flux-state problem within the $t$-$J$ model. The analysis of different parametrizations in the functional representation shows that (i) calculations which take into account constraints for…
Photoemission spectra for the isotropic two-leg t-J ladder are calculated at various hole-doping levels using exact diagonalization techniques. Low-energy sharp features caused by short-range antiferromagnetic correlations are observed at…
We demonstrate how to identify which physical processes dominate the low-energy spectral functions of correlated electron systems. We obtain an unambiguous classification through an analysis of the equation of motion for the electron…
Correlation effects in CuO$_2$ layers give rise to a complicated landscape of collective excitations in high-T$_{\rm c}$ cuprates. Their description requires an accurate account for electronic fluctuations at a very broad energy range and…
We consider a magnetic impurity coupled to both fermionic quasiparticles with a pseudogap density of states and bosonic spin fluctuations. Using renormalization group and large-N calculations we investigate the phase diagram of the…
The doping and temperature dependences of the Fermi arc in the staggered-flux, or the d-density wave, ordered phase of the t-J model are analyzed by the U(1) slave boson theory. Nontrivial behavior is revealed by the self-consistent…
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…
We present an exact diagonalization study of the doping dependence of the single particle Green's function in 16, 18 and 20 site clusters of t-J model. We find evidence for rigid-band behaviour starting from the half-filled case: upon…
We examine the spectral properties of a recently proposed theory of the intermediate temperature pseudogap metal phase of the cuprates. We show that this theory can be obtained from the familiar paramagnon theory of nearly antiferromagnetic…
We generalize the dynamical-mean field (DMFT) approximation by including into the DMFT equations some length scale via a (momentum dependent) ``external'' self-energy \Sigma_k. This external self-energy describes non-local dynamical…
We report on an exact solution of the nearly antiferromagnetic Fermi liquid spin fermion model in the limit \pi T << \omega_{sf}, which demonstrates that the broad high energy features found in ARPES measurements of the spectral density of…
We study pseudogap phenomena and Fermi-arc formation experimentally observed in typical two dimensional doped Mott insulators, namely, underdoped cuprate superconductors. To develop a physically unequivocal theory, we start from the…
Cluster dynamical mean field and maximum entropy analytical continuation methods are used to obtain theoretical estimates for the many-body density of states, electron self-energy, in-plane and c-axis optical conductivity and the $B_{1g}$…
Despite the intense theoretical and experimental effort, an understanding of the superconducting pairing mechanism of the high-temperature superconductors is still lacking. An additional puzzle is the unknown connection between the…
We propose that an extension of the exciton concept to doped Mott insulators offers a fruitful insight into challenging issues of the copper oxide superconductors. In our extension, new fermionic excitations called cofermions emerge in…