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Improved transport equations including correlations for electron-phonon systems. Comparison with exact solutions in one dimension

J. Fricke·V. Meden·C. Wohler·K. Schonhammer
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Abstract

We study transport equations for quantum many-particle systems in terms of correlations by applying the general formalism developed in an earlier paper to exactly soluble electron-phonon models. The one-dimensional models considered are the polaron model with a linear energy dispersion for the electrons and a finite number of electrons and the same model including a Fermi sea (Tomonaga-Luttinger model). The inclusion of two-particle correlations shows a significant and systematic improvement in comparison with the usual non-Markovian equations in Born approximation. For example, the improved equations take into account the renormalization of the propagation by the self-energies to second order in the coupling.

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J. Fricke, V. Meden, C. Wohler, K. Schonhammer. 1996-10-16. Improved transport equations including correlations for electron-phonon systems. Comparison with exact solutions in one dimension. https://doi.org/10.1006/aphy.1997.5623

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