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arXiv · 0801.3920

Three- and four-body interactions in colloidal systems

J. Dobnikar·M. Brunner·Jörg Baumgartl·H. H. von Grünberg·C. Bechinger
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Abstract

Three-body and four-body interactions have been directly measured in a colloidal system comprised of three (or four) charged colloidal particles. Two of the particles have been confined by means of a scanned laser tweezers to a line-shaped optical trap where they diffused due to thermal fluctuations. By means of an additional focused optical trap a third particle has been approached and attractive three-body interactions have been observed. These observations are in qualitative agreement with additionally performed nonlinear Poissson-Boltzmann calculations. Two configurations of four particles have been studied experimentally as well and in both cases a repulsive four-body interaction term has been observed.

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J. Dobnikar, M. Brunner, Jörg Baumgartl, H. H. von Grünberg, C. Bechinger. 2008-01-25. Three- and four-body interactions in colloidal systems. https://doi.org/10.1117/12.554610

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