title: Nonaffine heterogeneities and droplet fluctuations in an equilibrium crystalline solid.
abstract: We show, using molecular-dynamics simulations, that a two-dimensional Lennard-Jones solid exhibits droplet fluctuations characterized by nonaffine deviations from local crystallinity. The fraction of particles in these droplets increases as the mean density of the solid decreases and approaches ≈20% of the total number in the vicinity of the fluid-solid phase boundary. We monitor the geometry, local equation of state, density correlations, and Van Hove functions of these droplets. We provide evidence that these nonaffine heterogeneities should be interpreted as being droplet fluctuations from nearby metastable minima. The local excess pressure of the droplets plotted against the local number density shows a van der Waal loop with distinct branches corresponding to fluidlike compact and stringlike glassy droplets. The distinction between fluidlike and glassy droplets disappears above a well-defined temperature.
authors.affiliation: Advanced Materials Research Unit, S. N. Bose National Centre for Basic Sciences, Salt Lake, Kolkata 700091, India. tamoghna@bose.res.in
authors.forename: Tamoghna
authors.initials: T
authors.lastname: Das
authors.forename: Surajit
authors.initials: S
authors.lastname: Sengupta
authors.forename: Madan
authors.initials: M
authors.lastname: Rao
mesh_terms: D056004:Molecular Dynamics Simulation; D044367:Phase Transition; D013816:Thermodynamics