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Quasi-particle characteristics of the one-dimensional polaron

G. Ganbold
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Abstract

The main quasi-particle characteristics of the one-dimensional polaron are estimated within and beyond the most general Gaussian approximation at arbitrary electron-phonon coupling. We have derived explicitly the ground-state energy and the effective mass in the weak- and strong-coupling regimes. For arbitrary coupling, the Gaussian leading-order term of the polaron self energy improves the corresponding Feynman estimate and represents the lowest upper bound available. We have calculated the next non-Gaussian corrections. Taking into account systematically higher-order corrections does not perturb considerably the obtained results.

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G. Ganbold. 1999-10-21. Quasi-particle characteristics of the one-dimensional polaron. https://arxiv.org/abs/cond-mat/9910327

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