Quantitative theory of the random pinning glass transition and cooperative length scales
Chiara Cammarota, Sapienza, Rome
First direct observations of the ideal glass transition may be realized through the study of randomly-pinned systems, systems where a fraction of the particles are frozen in the position they have in an equilibrium configuration. As an initial guideline for experimental tests of the glass transition induced by this construction, aka Random Pinning Glass Transition (RPGT), I will show the results of first-principles computations by the Hypernetted chain approximation for Hard Sphere glasses which confirm the expected enhancement of glassy behaviour under the procedure of random pinning. I will present the phase diagram as a function of the concentration of pinned particles and of the global packing fraction, showing a line of RPGT and two spinodal lines for the competing liquid and glass phases. The other main results I will highlight are the first microscopic computation of cooperative length-scales characterizing amorphous order in glass-formers and quantitative information on a key thermodynamic quantity defined in proximity of the ideal glass transitions, the amorhpous surface tension.