Related papers: Polaron with Quadratic Electron-phonon Interaction
The nonadiabatic electron-phonon corrections for the superconducting pairing are investigated for a specific tight-binding model corresponding to a 2d square lattice. This permits to investigate the role of various specific properties like…
The translationally invariant diagrammatic quantum perturbation theory (TPT) is applied to the polaron problem on the 1D lattice, modeled through the Holstein Hamiltonian with the phonon frequency omega0, the electron hopping t and the…
We study the role of non-adiabatic Holstein electron-phonon coupling on the neutral-ionic phase transition of charge transfer crystals which can be tuned from continuous to discontinuous, using exact numerical diagonalization. The variation…
We study the Hubbard-Holstein model using slave-boson mean-field and a variation al Lang-Firsov transformation. We identify weak and strong e-ph coupling solutions, whose stability depends both on the bare e-ph coupling and on the…
We consider how electron-phonon interaction influences the insulator-metal transitions driven by doping in the strongly correlated system. Using the polaronic version of the generalized tight-binding method, we investigate a multiband…
We explore the quasiparticle properties of lattice polarons on the basis of a quite general electron-phonon Hamiltonian with a long-range displacement-type of interaction. To treat the dynamical quantum phonons without significant loss of…
The polaron formation is investigated in the intermediate regime of the Holstein model by using an exact diagonalization technique for the one-dimensional infinite lattice. The numerical results for the electron and phonon propagators are…
We describe a variational method to solve the Holstein model for an electron coupled to dynamical, quantum phonons on an infinite lattice. The variational space can be systematically expanded to achieve high accuracy with modest…
We introduce a variational wave-function to study the polaron formation when the electronic transfer integral depends on the relative displacement between nearest-neighbor sites giving rise to a non-local electron-phonon coupling with…
We describe the formation and properties of Holstein polarons in the entire parameter regime. Our presentation focuses on the polaron mass and radius, which we obtain with an improved numerical technique. It is based on the combination of…
The bound states of two electrons in the adiabatic Holstein-Hubbard model are studied numerically in one and two dimensions from the anticontinuous limit. This model involves a competition between a local electron-phonon coupling (with a…
In the weak regime, we suggest a model where superconductivity types I and II bind assuming an adiabatic hypothesis where the frequency of oscillation of free electrons is much smaller than of polarons coupled to phonons, and an itinerant…
We apply weak-coupling perturbation theory to the Holstein molecular crystal model in order to compute an electron-phonon correlation function characterizing the shape and size of the polaron lattice distortion in one, two, and three…
Many-polaron systems with finite charge-carrier density are often encountered experimentally. However, until recently, no satisfactory theoretical description of these systems was available even in the framework of simple models such as the…
To describe the interaction of molecular vibrations with electrons at a quantum dot contacted to metallic leads, we extend an analytical approach that we previously developed for the many-polaron problem. Our scheme is based on an…
We present a novel approach to electron-lattice interaction beyond the linear-coupling regime. Based on the solution of a Holstein-Peierls-type model, we derive explicit analytical expressions for the eigenvalue spectrum of the Hamiltonian,…
On the basis of the two-site polaron problem, which we solve by exact diagonalization, we analyse the spectral properties of polaronic systems in view of discerning localized from itinerant polarons and bound polaron pairs from an ensemble…
The optical properties of polarons are studied in the framework of the Holstein model by applying the dynamical mean-field theory. This approach allows to enlighten important quantitative and qualitative deviations from the limiting…
The adiabatic Born-Oppenheimer approximation is considered to be a robust approach that very rarely breaks down. Consequently, it is predominantly utilized to address various electron-phonon properties in condensed matter physics. By…
Attractive electron correlations due to an electron-vibron interaction (EVI) can overcome the direct Coulomb repulsion of polarons in strongly deformable molecular quantum dots (MQDs). If it realizes, a switching appears in the I-V…