Effects of Boson Dispersion in Fermion-Boson Coupled Systems

Abstract

We study the nonlinear feedback in a fermion-boson system using an extension of dynamical mean-field theory and the quantum Monte Carlo method. In the perturbative regimes (weak-coupling and atomic limits) the effective interaction among fermions increases as the width of the boson dispersion increases. In the strong coupling regime away from the anti-adiabatic limit, the effective interaction decreases as we increase the width of the boson dispersion. This behavior is closely related with complete softening of the boson field. We elucidate the parameters that control this nonperturbative region where fluctuations of the dispersive bosons enhance the delocalization of fermions.

arXiv comment14 pages RevTeX including 12 PS figures

References in corpus (4)

• On the Fermi Liquid to Polaron Crossover I: General Results
• Dynamical mean-field theory of the small polaron
• Ordering and Fluctuation of Orbital and Lattice Distortion in Perovskite Manganese Oxides
• Incoherent Charge Dynamics in Perovskite Manganese Oxides

Cited by in corpus (15)

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• Many-Body Approximation Scheme Beyond GW
• Non-linear feedback effects in coupled Boson-Fermion systems
• Extended Dynamical Mean Field Theory Study of the Periodic Anderson Model
• Semiclassical Analysis of Extended Dynamical Mean Field Equations
• Electron and phonon dispersions of the two dimensional Holstein model: Effects of vertex and non-local corrections
• Electron-Phonon Interactions in Correlated Systems: Adiabatic Expansion of the Dynamical Mean-Field Theory
• Extended Variational Cluster Approximation
• Tunneling system coupled to phonon: an analytical treatment
• The boson-fermion model with on-site Coulomb repulsion between fermions
• Pairing and polarization in systems with retarded interactions