Sedimentation profiles of systems with reentrant melting behavior - art. no. 011405

We examine sedimentation density profiles of star polymer solutions as an e xample of colloidal systems in sedimentation equilibrium that exhibit reent rant melting in their bulk phase diagram. Phase transitions between a fluid and a fluid with an intercalated solid are observed below a critical gravi tational strength alpha*. Characteristics of the two fluid-solid interfaces in the density profiles occurring in Monte Carlo simulations for alpha<<al pha>* are in agreement with scaling laws put forth in the framework of a ph enomenological theory. Furthermore, we detect density oscillations at the f luid-gas interface at high altitudes for high-gravitational fields, which a re verified with density-functional theory and should be observable in surf ace scattering experiments.