8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Thu 811:10-14:00P8.1Non-Gaussian fluctuation of time-averaged mean squaredisplacement in lipid bilayerTakuma Akimoto 11 Keio university, 3-14-1 Hiyoshi Kohokuku, Yokohama, 223-8522, Kanagawa,JapanAnomalous subdiffusion has attracted much attention from not only statistical physicists but alsofrom the biological community. This is because it is frequently observed for molecular transportin cells and plasma membranes with the aid of single tracking measurements. Moreover, intensivetheoretical studies have shown a novel statistical behavior of subdiffusion such as aging andweak ergodicity breaking. We introduce the scaling exponent of the relative fluctuations derivedby renewal theory to characterize non-Gaussian behavior. By performing a molecular dynamicssimulation of a lipid bilayer, we find that the time-averaged mean square displacement (TAMSD)in a lipid bilayer shows a non-Gaussian fluctuation, caused by a long trapping time. By extensiveanalysis for correlated motions, we clarify that anomalous transport in a lipid bilayer originatesfrom an anti-correlation as well as a long trapping time. Furthermore, we find that mobilities oflipid molecules are spatially inhomogeneously distributed and change with time. Unlike usual dynamicalheterogeneity, TAMSDs for all lipid molecules show transient subdiffusions, indicating anovel dynamical heterogeneity.1