Dynamics of five supercooled molecular liquids have been studied using optical heterodyne detected optical Kerr effect experiments. “Intermediate” time scale power law decays ($\sim 2\mathrm{p}\mathrm{s}$ to 1–10 ns) with temperature independent exponents close to $-1$ have been observed in all five samples from high temperature to $\sim T_c$, the mode-coupling theory (MCT) critical temperature. The amplitude of the intermediate power law increases with temperature as $[(T-T_c)/T_c{]}^{1/2}$. The results cannot be explained by standard MCT, and one possible explanation within MCT would require the higher order singularity scenario, thought to be highly improbable, to be virtually universal.

• Received 4 September 2002

DOI:https://doi.org/10.1103/PhysRevLett.90.197401