Related papers: Electron pairing: from metastable electron pair to…
We study possible quantum states of two correlated electrons in a two-dimensional crystal and find a metastable energy band of the electron pair between the two lowest single-electron bands. These metastable states result from the interplay…
When atoms are organized into a crystal, the single-electron energy levels of individual atoms form energy bands. However, there also exist electron-pair states in atoms. We found previously that the counterpart of these electron-pair…
We study the semiclassical dynamics of interacting electrons in a biased crystal lattice. A complex dynamical scenario emerges from the interplay between the Coulomb and the external electric fields. When the electrons are far apart, the…
The polaron features due to electron-phonon interactions with different coupling ranges are investigated by adopting a variational approach. The ground-state energy, the spectral weight, the average kinetic energy, the mean number of…
A large polaron is a quasiparticle that consists of a nearly free electron interacting with the phonons of a material, whose lattice parameters are much smaller than the polaron scale. The electron-phonon interaction also leads to an…
Based on the metastable electron-pair energy band in a two-dimensional (2D) periodic potential obtained previously by Hai and Castelano [J. Phys.: Condens. Matter 26, 115502 (2014)], we present in this work a Hamiltonian of many electrons…
he formation of the optical polaron and bipolaron in two-dimensional (2D) systems are studied in the intermediate electron-phonon coupling regime. The total energies of 2D polaron and bipolaron are calculated by using the Buimistrov-Pekar…
Bipolaron energies are calculated as a function of wave vector by a variational method of Gurari appropriate for weak or intermediate coupling strengths, for a model with electron-phonon interactions independent of phonon wave vectors and a…
The choice that a solid system "makes" when adopting a crystal structure (stable or metastable) is ultimately governed by the interactions between electrons forming chemical bonds. By analyzing 6 prototypical binary transition-metal…
We consider the two-band Hubbard model, where electrons from different bands interact through an on-site one- and two-particle hybridization. The proposed Hamiltonian makes it possible to construct an effective theory and answer the…
Coulomb interactions that occur in electronic structure calculations are correlated by allowing basis function components of the interacting densities to polarize, thereby reducing the magnitude of the interaction. Exchange integrals of…
We show that in anharmonic one-dimensional crystal lattices pairing of electrons or holes in a localized bisolectron state is possible due to coupling between the charges and the lattice deformation that can overcompensate the Coulomb…
Evidence for strong electron-phonon coupling in high-Tc cuprates is reviewed, with emphasis on the electron and phonon spectral functions. Effects due to the interplay between the Coulomb and electron-phonon interactions are studied. For…
We show that two added, excess electrons with opposite spins in one-dimensional crystal lattices with quartic anharmonicity may form a bisolectron, which is a localized bound state of the paired electrons to a soliton-like lattice…
We study the formation of spontaneous spin polarization in inhomogeneous electron systems with pair interaction localized in a small region that is not separated by a barrier from surrounding gas of non-interacting electrons. Such a system…
We consider a lattice model in which phonons scatter with pairs of electrons. All eigenvalues and eigenvectors can be obtained analytically. For a suitable choice of parameters the ground state consists of a Fermi sea of non-interacting…
Electrons coupled to local lattice deformations end up in selftrapped localized molecular states involving their binding into bipolarons when the coupling is stronger than a certain critical value. Below that value they exist as essentially…
In systems with linear electron-phonon interaction (EPI), bound states of polarons, or bipolarons, form by gaining energy from the lattice deformation. The quadratic EPI case is fundamentally different: bipolarons form because electrons…
Electron-phonon coupling, diagonal in a real space formulation, leads to polaron paradigm of smoothly varying properties. However, fundamental changes, namely the singular behavior of polarons, occur if non-diagonal pairing is involved into…
We study two correlated electrons in a nearest neighbour tight- binding chain, with both on site and nearest neighbour interaction. Both the cases of parallel and antiparallel spins are considered. In addition to the free electron band for…