Exploration of glass transition by pinning particles
Chiara Cammarota, IphT Saclay
Understanding the physical mechanism behind glass formation is a lasting problem in condensed matter physics. Interestingly from a theoretical point of view, there are reasons to think that the viscous slowing down of super-cooled liquids’ dynamics, preluding glass formation, is due to a new kind of thermodynamic transition, the glass transition. This is conjectured to be an entropy vanishing critical point with many peculiarities, notably an exponential growth of relaxation time.
I will first point out why assessing the mere existence of the glass transition in real systems is particularly difficult; indeed this issue is still largely questioned. Then I will present an idea, based on pinning particles at random from an equilibrium configuration, recently designed to solve this problem. Furthermore, I will show our predictions for the static and dynamical behaviors of glassy pinned systems, obtained through mean field computations and a non-perturbative Renormalization Group approach. I will finally discuss why the idea of pinning particles could be used to produce decisive tests for the existence of the glass transition in real systems.