Nonergodic diffusion of single atoms in a periodic potential
Kindermann F, Dechant A, Hohmann M, Lausch T, Mayer D, Schmidt F, Lutz E, Widera A (2017)
Publication Type: Journal article
Publication year: 2017
Journal
Book Volume: 13
Pages Range: 137-141
Journal Issue: 2
DOI: 10.1038/nphys3911
Abstract
Diffusion can be used to infer the microscopic features of a system from the observation of its macroscopic dynamics. Brownian motion accurately describes many diffusive systems, but non-Brownian and nonergodic features are often observed on short timescales. Here, we trap a single ultracold caesium atom in a periodic potential and measure its diffusion. We engineer the particle-environment interaction to fully control motion over a broad range of diffusion constants and timescales. We use a powerful stroboscopic imaging method to detect single-particle trajectories and analyse both non-equilibrium diffusion properties and the approach to ergodicity. Whereas the variance and two-time correlation function exhibit apparent Brownian motion at all times, higher-order correlations reveal strong non-Brownian behaviour. We additionally observe the slow convergence of the exponential displacement distribution to a Gaussian and-unexpectedly-a much slower approach to ergodicity, in perfect agreement with an analytical continuous-time random-walk model. Our experimental system offers an ideal testbed for the detailed investigation of complex diffusion processes.
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Germany (DE)How to cite
APA:
Kindermann, F., Dechant, A., Hohmann, M., Lausch, T., Mayer, D., Schmidt, F.,... Widera, A. (2017). Nonergodic diffusion of single atoms in a periodic potential. Nature Physics, 13(2), 137-141. https://dx.doi.org/10.1038/nphys3911
MLA:
Kindermann, Farina, et al. "Nonergodic diffusion of single atoms in a periodic potential." Nature Physics 13.2 (2017): 137-141.
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