The Roton Minimum: Is it a General Feature of Strongly Correlated Liquids?



The roton minimum is a deep minimum in the collective excitation spectrum of the liquid, forming around fairly high k -values. We have discovered, through MD simulations, that this appears to be a general feature of strongly coupled liquids and is ubiquitous in 2D and 3D Yukawa liquids. We suggest that the physical origin of the roton minimum has to be sought in the quasi-localization of particles in a strongly correlated liquid and in the ensuing formation of local microcrystals whose averaged frequency dispersion would show roton minimum-like feature (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)