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arXiv · 1106.3658

Broadening of the Derivative Discontinuity in Density Functional Theory

F. Evers·P. Schmitteckert
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Abstract

We clarify an important aspect of density functional theories, the broadening of the derivative discontinuity (DD) in a quantum system, with fluctuating particle number. Our focus is on a correlated model system, the single level quantum dot in the regime of the Coulomb blockade. We find that the DD-broadening is controlled by the small parameter $\Gamma/U$, where $\Gamma$ is the level broadening due to contacting and $U$ is a measure of the charging energy. Our analysis suggests, that Kondoesque fluctuations have a tendency to increase the DD-broadening, in our model by a factor of two.

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F. Evers, P. Schmitteckert. 2011-06-18. Broadening of the Derivative Discontinuity in Density Functional Theory. https://doi.org/10.1039/c1cp21247h

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