We study the diffusive behavior of colloidal particles which are confined to one-dimensional channels generated by scanning optical tweezers. At long times $t$, the mean-square displacement is found to scale as $t^{1/2}$, which is expected for systems where single-file diffusion occurs. In addition, we experimentally obtain the long-time, self-diffusive behavior from the short-time collective density fluctuations of the system as suggested by a recent analytical approach [M. Kollmann, Phys. Rev. Lett. 90, 180602 (2003)].

• Received 8 September 2003

DOI:https://doi.org/10.1103/PhysRevLett.93.026001