Experimental evidence for a structural-dynamical transition in trajectory space

Pinchaipat, R., Campo, M., Turci, F. ORCID: https://orcid.org/0000-0002-0687-0715, Hallett, J. E. ORCID: https://orcid.org/0000-0002-9747-9980, Speck, T. and Royall, C. P. (2017) Experimental evidence for a structural-dynamical transition in trajectory space. Physical Review Letters, 119 (2). 028004. ISSN 1079-7114 doi: 10.1103/PhysRevLett.119.028004

Abstract/Summary

Among the key insights into the glass transition has been the identification of a non-equilibrium phase transition in trajectory space which reveals phase coexistence between the normal supercooled liquid (active phase) and a glassy state (inactive phase). Here we present evidence that such a transition occurs in experiment. In colloidal hard spheres we find a non-Gaussian distribution of trajectories leaning towards those rich in locally favoured structures (LFS), associated with the emergence of slow dynamics. This we interpret as evidence for an non-equilibrium transition to an inactive LFS-rich phase. Reweighting trajectories reveals a first-order phase transition in trajectory space between a normal liquid and a LFS-rich phase. We further find evidence of a purely dynamical transition in trajectory space.