Liquids & Glass

Bifurcation analysis at singlet distribution (density profile) level identifies the thermodynamic phase transition point from liquid to crystal.

Bifurcation analysis at pair distribution (the angular component of the pair correlation function) level identifies the thermodynamic phase transition point from isotropic liquid to anisotropic liquid, e.g., the liquid to hexatics transition for two dimensional systems consisting of hard disks.

Transparent like a liquid, yet rigid like a rock. The details of how a liquid acquires amorphous rigidity upon cooling and forms a glass are still not well understood. This is partly because in both real experiments and computer simulations, the dynamics of the system slow down dramatically near the transition and the final “glassy” states are clearly dependent on the dynamical non-equilibrium cooling protocols. The question of whether there exists a true underlying phase transition to a glass state is still under heated debate as the identification of the order parameter is challenging. Recent observations reveal that the dynamics of supercooled liquids is spatially heterogeneous, displaying both growing dynamic length scales and growing timescales. However, investigations have mostly been focused on dynamic correlation functions, e.g., the dynamic four-point susceptibility, instead of static correlation functions. Here in our group we focus on the study of possible static structural changes at triplet level during the glass transition. This study is also useful for the understanding of hydrophobicity, where distribution of water molecules around an oil solute is studied.