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arXiv · 1410.0237

Many-body theory of the neutralization of strontium ions on gold surfaces

M. Pamperin·F. X. Bronold·H. Fehske
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Abstract

Motivated by experimental evidence for mixed-valence correlations affecting the neutralization of strontium ions on gold surfaces we set up an Anderson-Newns model for the Sr:Au system and calculate the neutralization probability $\alpha$ as a function of temperature. We employ quantum-kinetic equations for the projectile Green functions in the finite$-U$ non-crossing approximation. Our results for $\alpha$ agree reasonably well with the experimental data as far as the overall order of magnitude is concerned showing in particular the correlation-induced enhancement of $\alpha$. The experimentally found non-monotonous temperature dependence, however, could not be reproduced. Instead of an initially increasing and then decreasing $\alpha$ we find over the whole temperature range only a weak negative temperature dependence. It arises however clearly from a mixed-valence resonance in the projectile's spectral density and thus supports qualitatively the interpretation of the experimental data in terms of a mixed-valence scenario.

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M. Pamperin, F. X. Bronold, H. Fehske. 2014-10-01. Many-body theory of the neutralization of strontium ions on gold surfaces. https://doi.org/10.1103/physrevb.91.035440

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