Signatures of polaron formation in systems with local
and non-local electron-phonon couplings |
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Authors: | E?Piegari C A?Perroni Email author" target="_blank">V?CataudellaEmail author |
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Institution: | (1) Dipartimento di Scienze Fisiche, Universitá di Napoli Federico II , via Cinthia, 80126 Napoli, Italy;(2) Coherentia-INFM, UdR di Napoli, via Cinthia, 80126 Napoli, Italy |
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Abstract: | Polaron formation is investigated in a one-dimensional chain by
taking into account both the local Holstein and the non-local SSH
electron-phonon interactions. The study of the adiabatic regime
points out that the combined effects of the two interactions are
important mainly in the weak coupling regime. Thus, using the
weak-coupling perturbation theory, spectral weights, effective
masses, polaronic phase-diagram, and band structures are
discussed. Contrarily to what happens in the Fröhlich and
Holstein models, we find that the ratio between the coherent
spectral weight and the mass renormalization ratio is greater than
1. Moreover, we show that the non-local electron-phonon
interaction is responsible for the largest deviations of the band
structure from the cosine shape of the free energy band. |
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Keywords: | |
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