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Photoemission spectroscopy and sum rules in dilute electron-phonon systems

P. E. Kornilovitch
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Abstract

A family of exact sum rules for the one-polaron spectral function in the low-density limit is derived. An algorithm to calculate energy moments of arbitrary order of the spectral function is presented. Explicit expressions are given for the first two moments of a model with general electron-phonon interaction, and for the first four moments of the Holstein polaron. The sum rules are linked to experiments on momentum-resolved photoemission spectroscopy. The bare electronic dispersion and the electron-phonon coupling constant can be extracted from the first and second moments of spectrum. The sum rules could serve as constraints in analytical and numerical studies of electron-phonon models.

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P. E. Kornilovitch. 2002-02-11. Photoemission spectroscopy and sum rules in dilute electron-phonon systems. https://doi.org/10.1209/epl%2Fi2002-00187-x

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