Dynamic transition and its structural correlation

Speaker: Limei Xu, Peking University

When: February 17, 2017 (Fri), 01:30PM to 02:30PM (add to my calendar)
Location: SCI 352

This event is part of the Biophysics/Condensed Matter Seminar Series.

Dynamic transition from Arrhenius to non-Arrhenius behavior is reported in many glass-forming liquids. The mechanism of such phenomenon was extensively debated. Different scenarios, such as phase transition, partial crystallization, or glass transition, were been proposed to understand the dynamic transition. In this presentation, I will talk about our recent study on the dynamic crossover in models of molecular, atomic and metallic systems. Our studies show that the structural heterogeneity is the origin of the dynamic transition. For instance, when the size of the largest cluster consisting of densely packed atoms starts to increase sharply, the dynamics starts to deviate from the high temperature behavior, while the largest cluster percolates the entire system and forms stable 3-dimentional network structures, it follows the low temperature behavior. The potential energy landscape method study also confirms such scenario. Our study directly link the dynamic crossover with structure inhomogeneity, thus provide a more general picture for the dynamic transitions in glass-forming liquids.

a short CV

Limei Xu received her Ph.D. degree from the Department of Physics, Boston University and did her postdoc in the Chemistry Department, University of Utah. In 2008 she joined the Advanced Institute of Materials Research (WPI-AIMR) at Tohoku University as an assistant professor. In 2011 she was selected as the Junior 1000 Talents by the Recruitment Program of Global Experts of China and took the associate professor position at Peking University in China. She was awarded the Distinguished Young Scholars by the National Science Foundation in 2015. Her current research interests include critical and supercritical phenomena in condensed matter physics, surface science and nonequilibrium statistical physics.