[SY-M3] Structural-dynamical phase transition in the phase space of histories of a polydisperse hard sphere liquid
The glass transition is a longstanding problem in condensed matter physics. One of the main points of discussion is whether it is possible to characterize the glass transition using structural arguments, together with dynamical ones. In fact, it is known that supercooled liquids do not show major changes in their global (two-point) structure upon cooling while displaying a dramatic change in their dynamical properties. Recent insights have brought attention to the local structure instead. For a wide range of model glassformers, it is possible to identify certain geometric motifs that minimize the local free energy. These motifs are referred to as Locally Favourite Structures (LFS) and are found to be growing in correlation with the slowing-down of the dynamics. Using tools from large deviation theory and statistical mechanics of histories, it was recently possible to identify for some model glassformers a structural-dynamical transition between the supercooled liquid state and a state composed of trajectories rich in LFS with very slow dynamics. We present here a study of this transition for a fundamental atomistic model glassformer, the polydisperse hard sphere liquid. We reveal the first-order nature of the transition by employing finite size scaling on the length of the histories of the system, and a phase diagram is constructed as a function of the density versus the local order, and the density versus the degree of mobility of the system.