Europhys. Lett., 50 (4), p. 447 (2000)

Non-conventional screening of the Coulomb interaction in low-dimensional and finite-size systems

J. van den Brink ^1,2 and G. A. Sawatzky ²

¹Department of Applied Physics, University of Twente
P.O. Box 217, 7500 AE Enschede, The Netherlands
²Laboratory of Applied and Solid State Physics, Materials Science Center,
University of Groningen - Nijenborgh 4, 9747 AG Groningen, The Netherlands

PACS :
31.25.Qm - Electron-correlation calculations for polyatomic molecules
71.20.Tx - Fullerenes and related materials; intercalation compounds
71.27.+a - Strongly correlated electron systems; heavy fermions

Abstract:

We study the screening of the Coulomb interaction in non-polar systems by polarizable atoms. We show that in low dimensions and small finite-size systems this screening deviates strongly from that conventionally assumed. In fact in one dimension the short-range interaction is strongly screened and the long-range interaction is anti-screened thereby strongly reducing the gradient of the Coulomb interaction and therefore the correlation effects. We argue that this effect explains the success of mean-field single-particle theories for large molecules.

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