Related papers: Friedel oscillations in a two-band Hubbard model f…
In this work, we investigate impurity-induced Friedel oscillations in the doped two-dimensional Hubbard model, focusing on the role of holon and doublon excitations. We show that weak impurities, due to the non-fermionic nature of the…
When immersed in a see of cold electrons, local impurities give rise to density modulations known as Friedel oscillations. In spite of the generality of this phenomenon, the exact shape of these modulations is usually computed only for…
We study the Cu and O spectral density of states and the optical conductivity of CuO_2 planes using an effective generalized one-band Hubbard model derived from the extended three-band Hubbard model. We solve exactly a square cluster of 10…
Using the Hubbard chain at quarter filling as a model system, we study the ground state properties of highly doped antiferromagnets. In particular, the Hubbard chain at quarter filling is unstable against 2k_F- and 4k_F-periodic potentials,…
We investigate the nature of the electronic ground state and electron-lattice couplings for doped chains of CuO_4 plaquettes or CuO_6 octahedra. The undoped configuration implies here Cu 3d^9 and O 2p^6 formal valence states. The results of…
The doping and temperature dependent optical conductivity spectra of the quasi-two-dimensional Ca_{2-x}Sr_xRuO_4 (0.0=<x=<2.0) system were investigated. In the Mott insulating state, two electron correlation-induced peaks were observed…
A model of CuO$_2$ planes of cuprate perovskites, containing $d_{x^2-y^2}$ copper orbitals and symmetric combinations of oxygen $p_\sigma$ orbitals, is investigated using the strong coupling diagram technique. This approach allows one to…
An antiferromagnetic Hund coupling in multiorbital Hubbard systems induces orbital freezing and an associated superconducting instability, as well as unique composite orders in the case of an odd number of orbitals. While the rich phase…
Quantum oscillations in hole doped high temperature superconductors are difficult to understand within the prevailing views. An emerging idea is that of a putative normal ground state, which appears to be a Fermi liquid with a reconstructed…
To explain the low frequencies of quantum oscillations observed in lightly doped cuprates, we consider the two-dimension Hubbard model supplemented with the perpendicular magnetic field. For large Hubbard repulsions, the electron spectrum…
The density matrix renormalization group method for ladders works much more efficiently with open boundary conditions. One consequence of these boundary conditions is groundstate charge density oscillations that often appear to be nearly…
Experiments have revealed multiple quantum oscillation frequencies in underdoped high temperature superconductor $\mathrm{YBa_{2}Cu_{3}O_{6+\delta}}$, corresponding to approximately 10% doping, which contain $\mathrm{CuO}$ bilayers in the…
In this article we study the conditions under which holographic metallic states display Friedel oscillations. We focus on systems where the bulk charge density is not hidden behind a black hole horizon. Understanding holographic Friedel…
Motivated by recent experimental progress on iron-based ladder compounds, we study the doped two-orbital Hubbard model for the two-leg ladder BaFe$_2$S$_3$. The model is constructed by using {\it ab initio} hopping parameters and the ground…
We examine the orbital and magnetic order of the two orbital Hubbard model within dynamical mean field theory. The model describes the low energy physics of a partially filled $e_g$-band as can be found in some transition metal compounds.…
Though most fermionic Mott insulators order at low temperatures, ordering is ancillary to their insulating behaviour. Our emphasis here is on disentangling ordering from the intrinsic strongly correlated physics of a doped half-filled band.…
The normal and the superconducting state of two coupled CuO_2 layers in the High-T_c superconductors are investigated by using the bilayer Hubbard model, the FLEX approximation on the real frequency axis and the Eliashberg theory. We find…
Doping of strongly layered ionic oxides is an established paradigm for creating novel electronic behavior. This is nowhere more apparent than in superconductivity, where doping gives rise to high temperature superconductivity in cuprates…
The phase separation instability occurring with increasing nearest-neighbor repulsion V in a two-band Hubbard model (CuO chain) is discussed. Quantum Monte Carlo simulations indicate that this transition is associated with a level-crossing…
We study Friedel oscillations (FOs) in two-dimensional topological materials with Mexican hat band dispersion, which attract great interest due to the bunch of its inherent non-trivial features, including the Van Hove singularity, doubly…