Related papers: Spectral Function of an Electron Coupled to Hard C…

We study the spectrum of the Fr\"ohlich Hamiltonian for the polaron at fixed total momentum. We prove the existence of excited eigenvalues between the ground state energy and the essential spectrum at strong coupling. In fact, our main…

Hyperbolic phonon polaritons (HPhPs) in hexagonal boron nitride (hBN) enable the direct manipulation of mid-infrared light at nanometer scales, many orders of magnitude below the free-space light wavelength. High resolution monochromated…

We study the small-polaron problem of a single electron interacting with the lattice for the Holstein model in the adiabatic limit on a comb lattice, when the electron-phonon interaction acts only on the base sites. The ground state…

The work is devoted to obtaining the 1D bipolaron functional by Holstein method for the continuum approximation. We analyzed the effect of electron correlations associated with the direct dependence of the wave function of the electron…

We present a model calculation of the spectral function of an electron in a superconducting resonating valence bond (RVB) state. The RVB state, described by the phase-string mean field theory is characterized by three important features:…

We investigate the interaction of strongly correlated electrons with phonons in the frame of the Hubbard-Holstein model. The electron-phonon interaction is considered to be strong and is an important parameter of the model besides the…

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,…

We study the effect of strong electron-phonon interactions on the damping of the Higgs amplitude mode in superconductors by means of non-equilibrium dynamical mean-field simulations of the Holstein model. In contrast to the BCS dynamics, we…

Looking for superconductors with higher transition temperature requires a guiding principle. In conventional superconductors, electrons pair up into Cooper pairs via the retarded attraction mediated by electron-phonon coupling.…

We derive the shape of the high-energy features due to a weakly coupled boson in cuprate superconductors, as seen experimentally in Bi_2 Sr_2 Ca_1 Cu_2 O_8+x (BSCCO) by Lee et al. [Nature (London) 442, 546 (2006)]. A simplified model is…

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…

We revisit the two-site Hubbard-Holstein model by using extended phonon coherent states. The nontrivial singlet bipolaron is studied exactly in the whole coupling regime. The ground-state (GS) energy and the double occupancy probability are…

When the electron-phonon coupling is quadratic in the phonon coordinates, electrons can pair to form bipolarons due to phonon zero-point fluctuations, a purely quantum effect. We study superconductivity originating from this pairing…

Theoretical studies suggest that Su-Schrieffer-Heeger-like electron-phonon ($e$-ph) interactions can mediate high-temperature bipolaronic superconductivity that is robust against repulsive electron-electron interactions. Here we present a…

Using the self-consistent Born approximation, and the corresponding wave function of the magnetic polaron, we calculate the quasiparticle weight corresponding to destruction of a real electron (in contrast to creation of a spinless holon),…

The single-polaron band structure of the Holstein model in one and two dimensions is studied using a new form of resummed strong-coupling perturbation theory. Well converged results are obtained for phonon frequencies of the order of the…

An analytical approach to the one-dimensional spinless Holstein model is proposed, which is valid at finite charge-carrier concentrations. Spectral functions of charge carriers are computed on the basis of self-energy calculations. A…

It can be shown that the bosonic degree of freedom of the tightly bound on-site electron pairs could be separated as Schwinger bosons. This is implemented by projecting the whole Hilbert space into the Hilbert subspace spanned by states of…

It is widely accepted that phonon-mediated high-temperature superconductivity is impossible at ambient pressure, because of the very large effective masses of polarons/bipolarons at strong electron-phonon coupling. Here we challenge this…

A new variational approach is proposed at zero temperature for a finite density of charge carriers in order to study ground state features of the Frohlich model including electron-electron and electron-phonon interactions. Within the…