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arXiv · 0804.0730

Influence of non-conservative optical forces on the dynamics of optically trapped colloidal spheres: The fountain of probability

Yohai Roichman·Bo Sun·Allan Stolarski·David G. Grier
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Abstract

We demonstrate both experimentally and theoretically that a colloidal sphere trapped in a static optical tweezer does not come to equilibrium, but rather reaches a steady state in which its probability flux traces out a toroidal vortex. This non-equilibrium behavior can be ascribed to a subtle bias of thermal fluctuations by non-conservative optical forces. The circulating sphere therefore acts as a Brownian motor. We briefly discuss ramifications of this effect for studies in which optical tweezers have been treated as potential energy wells.

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Yohai Roichman, Bo Sun, Allan Stolarski, David G. Grier. 2008-04-04. Influence of non-conservative optical forces on the dynamics of optically trapped colloidal spheres: The fountain of probability. https://doi.org/10.1103/physrevlett.101.128301

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