Test of the diffusing-diffusivity mechanism using near-wall colloidal dynamics

Mpumelelo Matse; John Bechhoefer

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arXiv · 1602.07644

Test of the diffusing-diffusivity mechanism using near-wall colloidal dynamics

Mpumelelo Matse·John Bechhoefer

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Abstract

The diffusing-diffusivity mechanism proposed by Chubynsky and Slater [PRL 113, 098302, 2014] predicts that, in environments where the diffusivity changes gradually, the displacement distribution becomes non-Gaussian, even though the mean-squared displacement (MSD) grows linearly with time. Here, we report single-particle tracking measurements of the diffusion of colloidal spheres near a planar wall. Because the local effective diffusivity is known, we have been able to carry out the first direct test of this mechanism for diffusion in inhomogeneous media.

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Mpumelelo Matse, John Bechhoefer. 2016-02-24. Test of the diffusing-diffusivity mechanism using near-wall colloidal dynamics. https://arxiv.org/abs/1602.07644

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