title: Universal spectra of coherent atoms in a recurrent random walk.
abstract: We report an experiment that directly measures the Laplace transform of the recurrence probability in one dimension using electromagnetically induced transparency (EIT) of coherent atoms diffusing in a vapor cell filled with buffer gas. We find a regime where the limiting form of the complex EIT spectrum is universal and only depends on the effective dimensionality in which the random recurrence takes place. In an effective one-dimensional diffusion setting, the measured spectrum exhibits power-law dependence over two decades in the frequency domain with a critical exponent of 0.56 close to the expected value 0.5.
authors.affiliation: Department of Physics of Complex Systems, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: R
authors.initials: R
authors.lastname: Pugatch
authors.forename: O
authors.initials: O
authors.lastname: Firstenberg
authors.forename: M
authors.initials: M
authors.lastname: Shuker
authors.forename: N
authors.initials: N
authors.lastname: Davidson