Inhomogeneity of a harmonically confined Yukawa system
A crystalline system of strongly screened Yukawa particles in a harmonic trap is under consideration. We show that structural and dynamic properties of confined Yukawa crystals are fundamentally nonuniform. The average interparticle distance, thermal oscillation amplitude, and Lindemann and inverse coupling parameters are found to increase with the radial distance from the center of a structure. We verify the inhomogeneity of these parameters by molecular dynamics simulations and the analytical approach. Analytical formulas are in good agreement with a dusty plasma experiment. The obtained results might be important for the theory of crystal formation and phase transitions in dusty plasmas, colloidal suspensions, and Coulomb crystals.