Deconstructing the glass transition through critical experiments on colloids

Abstract

The glass transition is the most enduring grand-challenge problem in contemporary condensed matter physics. Here, we review the contribution of colloid experiments to our understanding of this problem. First, we briefly outline the success of colloidal systems in yielding microscopic insights into a wide range of condensed matter phenomena. In the context of the glass transition, we demonstrate their utility in revealing the nature of spatial and temporal dynamical heterogeneity. We then discuss the evidence from colloid experiments in favor of various theories of glass formation that has accumulated over the last two decades. In the next section, we expound on the recent paradigm shift in colloid experiments from an exploratory approach to a critical one aimed at distinguishing between predictions of competing frameworks. We demonstrate how this critical approach is aided by the discovery of novel dynamical crossovers within the range accessible to colloid experiments. We also highlight the impact of alternate routes to glass formation such as random pinning, trajectory space phase transitions and replica coupling on current and future research on the glass transition. We conclude our review by listing some key open challenges in glass physics such as the comparison of growing static length scales and the preparation of ultrastable glasses that can be addressed using colloid experiments.

PACS:

• 64.70.P-glass transitions
• 81.05.Kf glasses
• 64.70.qj criticality of glass transitions
• 63.50.Lm disordered solids
• 64.70.pv glass transitions in colloids
• 82.70.Dd colloids
• 87.64.mk confocal microscopy
• 07.60.Pb optical microscopy

Keywords:

• glass transition
• colloids
• microscopy
• holographic optical tweezers
• random first-order transition theory
• dynamical facilitation
• mode coupling theory
• geometric frustration
• dynamical heterogeneity
• Stokes–Einstein relation
• ellipsoids
• crossovers
• random pinning
• replica coupling
• trajectory space phase transitions
• ultrastable glasses

Acknowledgements

We thank K. Hima Nagamanasa for her invaluable contributions to our collaborative effort in this field. We also thank Chandan Mishra for fruitful collaborations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

S.G. thanks the Council for Scientific and Industrial Research (CSIR), India, for a Shyama Prasad Mukherjee Fellowship and the Department of Science and Technology (DST), India, for financial support. R.G. thanks the International Centre for Materials Science (ICMS) and the Sheikh Saqr Laboratory (SSL), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR) for financial support and A.K.S. thanks DST, India, for support under the J.C. Bose Fellowship.