Related papers: Charge Transfer Excitations in Insulating Copper O…
Very high energy resolution photoemission experiments on high quality samples of optimally doped Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta}$ show new features in the low-energy electronic excitations. A marked change in the binding energy and…
Copper oxide high temperature superconductors universally exhibit multiple forms of electronically ordered phases that break the native translational symmetry of the CuO2 planes. The interplay between these orders and the superconducting…
In the present paper we propose a doubly orbitally degenerate narrow-band model with correlated hopping. The peculiarity of the model is taking into account the matrix element of electron-electron interaction which describes intersite…
Observation of interlayer, charge-transfer (CT) excitons in van der Waals heterostructures (vdWHs) based on 2D-2D systems has been well investigated. While conceptually interesting, these charge transfer excitons are highly delocalized and…
A spin-fermion model that captures the charge-transfer properties of Cu-based high critical temperature superconductors is introduced and studied via Monte Carlo simulations. The strong Coulomb repulsion among $d$-electrons in the Cu…
The transition mechanism in high temperature cuprate superconductors is an outstanding puzzle. A previous suggestion on the role of non-linear local lattice instability modes on the microscopic pairing mechanism in high temperature cuprate…
The effects of the nearest neighbour Coulomb repulsion, V, are considered in the one dimensional copper-oxide chain using the modified Lanczos method. Above a critical value of V we find that charge transfer excitons are the lowest lying…
A consistent description of low-energy charge and spin responses of the insulating Sr_2CuO_2Cl_2 lamellar system is found in the framework of a one-band Hubbard model which besides $U$ includes hoppings up to 3^{rd} nearest-neighbors. By…
We develop a general theory of electron--hole recombination in organic light emitting diodes that leads to formation of emissive singlet excitons and nonemissive triplet excitons. We briefly review other existing theories and show how our…
Excitons, composite electron-hole quasiparticles, are known to play an important role in optoelectronic phenomena in many semiconducting materials. Recent experiments and theory indicate that the band-gap optics of the newly discovered…
Spin-singlet and spin-triplet internal transitions of quasi-two-dimensional, negatively charged magneto-excitons (X-) and their evolution with excess electron density have been studied in GaAs/AlGaAs quantum-wells by optically detected…
Quantum--Mechanical methods that are both computationally fast and accurate are not yet available for electronic excitations having charge transfer character. In this work, we present a significant step forward towards this goal for those…
We investigated excitation spectra of the one-dimensional chain compound Sr$_{2}$CuO$_{3}$. The small peak at 2.3 eV in the loss function was turned to correspond to the strong charge transfer transition at 1.8 eV in conductivity. It has…
We study the Mott transition from a metal to cluster Mott insulators in the 1/4- and 1/8-filled pyrochlore lattice systems. It is shown that such Mott transitions can arise due to charge localization in clusters or in tetrahedron units,…
Room-temperature Coulomb blockade of charge transport through composite nanostructures containing organic inter-links has recently been observed. A pronounced charging effect in combination with the softness of the molecular links implies…
In the aim of completing our previous efforts devoted to local and Rydberg transitions in organic compounds, we provide a series of highly-accurate vertical transition energies for intramolecular charge-transfer transitions occurring in…
Excitons, the bosonic quasiparticle emerging from Coulomb interaction between electrons and holes, will undergo a Bose-Einstein condensation(BEC) and transition into a superfluid state with global phase coherence at low temperatures. An…
A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated…
The three-band model relevant to high temperature copper-oxide superconductors is solved using single-site dynamical mean field theory and a tight-binding parametrization of the copper and oxygen bands. For a band filling of one hole per…
We present a valence transition model for electron- and hole-doped cuprates, within which there occurs a discrete jump in ionicity Cu$^{2+} \to$ Cu$^{1+}$ upon doping, at or near optimal doping in the electron-doped compounds and at the…