@misc{10481/69911,
year = {2021},
month = {7},
url = {http://hdl.handle.net/10481/69911},
abstract = {According to the classical theory of Brownian motion, the mean-squared displacement of diffusing
particles evolves linearly with time, whereas the distribution of their displacements is Gaussian. However,
recent experiments on mesoscopic particle systems have discovered Brownian yet non-Gaussian regimes
where diffusion coexists with an exponential tail in the distribution of displacements. Here we show that,
contrary to the present theoretical understanding, the length scale λ associated with this exponential
distribution does not necessarily scale in a diffusive way. Simulations of Lennard-Jones systems reveal a
behavior λ ∼ t1=3 in three dimensions and λ ∼ t1=2 in two dimensions. We propose a scaling theory based
on the idea of hopping motion to explain this result. In contrast, simulations of a tetrahedral gelling system,
where particles interact by a nonisotropic potential, yield a temperature-dependent scaling of λ.
We interpret this behavior in terms of an intermittent hopping motion. Our findings link the Brownian
yet non-Gaussian phenomenon with generic features of glassy dynamics and open new experimental
perspectives on the class of molecular and supramolecular systems whose dynamics is ruled by rare events.},
organization = {German Research Foundation (DFG)	ME 1535/7-1},
organization = {European Commission through the Marie Sklodowska-Curie Individual Fellowship	840195},
publisher = {American Physical Society},
title = {Length Scales in Brownian yet Non-Gaussian Dynamics},
doi = {10.1103/PhysRevX.11.031002},
author = {Miotto, José M. and Pigolotti, Simone and Chechkin, Aleksei V. and Roldán Vargas, Sándalo},
}