相关论文: Optimal Boson energy for superconductivity in the …

Non-diagonal couplings to a bosonic bath completely change polaronic dynamics, from the usual diagonally-coupled paradigm of smoothly-varying properties. We study, using analytic and numerical methods, a model having both diagonal Holstein…

We propose a numerical method which embeds the variational non-Gaussian wavefunction approach within exact diagonalization, allowing for efficient treatment of correlated systems with both electron-electron and electron-phonon interactions.…

Determining the range of validity of Migdal's approximation for electron-phonon ($e$-ph) coupled systems is a long-standing problem. Many attempts to answer this question employ the Holstein Hamiltonian, where the electron density couples…

We analyze fulleride superconductivity at experimental doping levels, treating the electron-electron and electron-phonon interactions on an equal footing, and establish the existence of novel physics which helps explain the unusually high…

We investigate the dynamical effects of pairing interaction on superconductivity in BCS-BEC crossover by studying the Holstein model at half-filling where the electron-phonon coupling $g$ controls the crossover. The dynamical mean-field…

Employing unbiased sign-problem-free quantum Monte Carlo, we investigate the effects of long-range Coulomb forces on BEC of bipolarons using a model of bond phonon-modulated electron hopping. In absence of long-range repulsion, this model…

An exact diagonalization technique is used to investigate the low-lying excited polaron states in the Holstein model for the infinite one-dimensional lattice. For moderate values of the adiabatic ratio, a new and comprehensive picture,…

Superfluid helium, describable by a two-component order parameter, exhibits only the Bogolubov mode with energy $\to 0$ at long wavelengths, while a Lorentz-invariant theory with a two-component order parameter exhibits a finite energy mode…

We present simple qualitative estimates for the maximal superconducting transition temperature, which may be achieved due to electron - phonon coupling in Eliashberg-McMillan theory. It is shown that in the limit of very strong coupling the…

The density driven Mott transition is studied by means of Dynamical Mean-Field Theory in the Hubbard-Holstein model, where the Hubbard term leading to the Mott transition is supplemented by an electron-phonon (e-ph) term. We show that an…

We derive an effective polaronic interaction Hamiltonian, {\it exact to second order in perturbation}, for the spinless one-dimensional Holstein model. The small parameter is given by the ratio of the hopping term ($t$) to the polaronic…

We study, at zero temperature, the dynamics of a single electron in a Holstein model augmented by site-diagonal, binary-alloy type disorder. The average over the phonon vacuum and the alloy configurations is performed within a generalized…

Superconducting systems based on attractive electron-phonon interactions are the ones which are best understood at a fundamental level. They are well described using Eliashberg theory, which, unlike BCS theory, explicitly takes into account…

We study the effects of Kohn anomalies on the superconducting properties in electron- and hole-doped cases of monolayer blue phosphorene, considering both adiabatic and non-adiabatic phonon dispersions using first-principles calculations.…

We investigate the low-energy properties of the Holstein polaron through calculation of the q-dependent phonon spectral function using an improved exact-diagonalization technique, defined over a variational Hilbert space. We perform a…

We provide a comprehensive solution to the lattice dynamics problem in the two dimensional Holstein model at finite electron density and finite temperature. We work in the physically relevant adiabatic regime and vary the electron-phonon…

On a basis of earlier substantiated expression for effective potential of electron-electron attraction in metals the assumption of an opportunity of formation of classically bound pairs is put forward. It was shown that in distinction from…

A Bose--Einstein condensate of exciton polaritons coexisting with a Fermi gas of electrons has been recently proposed as a promising system for realisation of room-temperature superconductivity [Phys. Rev. Lett., 104, 106402 (2010)]. In…

The electron-phonon interaction corresponding to the Holstein model (with Coulomb repulsion) is simulated in infinite dimensions using a novel quantum Monte Carlo algorithm. The thermodynamic phase diagram includes commensurate…

We investigate the scattering of an electron by phonons in a small structure between two one-dimensional tight-binding leads. This model mimics the quantum electron transport through atomic wires or molecular junctions coupled to metallic…