Bipolarons and polarons in the Holstein-Hubbard model: Analogies and differences

Abstract

The single bipolaron problem is examined in the context of the 1D Holstein-Hubbard model, emphasizing analogies and differences with respect to the complementary single polaron physics. The bipolaron band structure below the phonon threshold is revealed, showing a complex relationship between numerous excited bands as the adiabatic limit is approached. Light bipolarons with significant binding energy, the stability of large bipolarons, the small to large bipolaron crossover as a function of the Hubbard repulsion, as well as the bipolaron dissociation, are investigated in detail, disentangling adiabatic, nonadiabatic and lattice coarsening effects. It is emphasized that condensation of bipolarons occurs in the dilute limit only at very low temperatures.

12 pages, 7 figures

References in corpus (9)

• Two-dimensional Hubbard-Holstein bipolaron
• Superlight small bipolarons in the presence of strong Coulomb repulsion
• Temperature- and quantum phonon effects on Holstein-Hubbard bipolarons
• Superlight small bipolarons
• Phase diagram of the Holstein polaron in one dimension
• Emergence of states in the phonon spectral function of the Holstein polaron below and above the one-phonon continuum
• Relevant coherent states method for the quantum adiabatic dynamics of lattice-coupled charge carriers
• Quantum adiabatic polarons by translationally invariant perturbation theory
• Polaron and bipolaron dispersion curves in one dimension for intermediate coupling

Cited by in corpus (4)

• Dissociation of a Hubbard--Holstein bipolaron driven away from equilibrium by a constant electric field
• Going beyond the linear approximation in describing electron- phonon coupling: relevance for the Holstein model
• Stable bipolarons in open quantum systems
• Spectral function of a bipolaron coupled to dispersive optical phonons