Effects of the electron-phonon coupling near and within the insulating Mott phase

Abstract

The role of the electron-phonon interaction in the Holstein-Hubbard model is investigated in the metallic phase close to the Mott transition and in the insulating Mott phase. The model is studied by means of a variational slave boson technique. At half-filling, mean-field static quantities are in good agreement with the results obtained by numerical techniques. By taking into account gaussian fluctuations, an analytic expression of the spectral density is derived in the Mott insulating phase showing that an increase of the electron-phonon coupling leads to a sensitive reduction of the Mott gap through a reduced effective repulsion. The relation of the results with recent experimental observations in strongly correlated systems is discussed.

4 pages, 4 figures

References in corpus (2)

• First- and Second Order Phase Transitions in the Holstein-Hubbard Model
• Quantum lattice dynamical effects on the single-particle excitations in 1D Mott and Peierls insulators

Cited by in corpus (5)

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• Extended Gutzwiller wavefunction for the Hubbard-Holstein model
• Competing Correlated Insulators in multi-orbital systems coupled to phonons
• Intertwined fluctuations and isotope effects in the Hubbard-Holstein model on the square lattice from functional renormalization