Ramanujan Auditorium

Athermal Elasticity: From Crystalline to Amorphous Packings

Kabir Ramola

TIFR Hyderabad

Elasticity is a fundamental macroscopic property that emerges in any
collection of interacting particles. However, at sufficiently low
temperatures where thermal fluctuations are negligible, a free
energetic description of such macroscopic properties is not available.
Granular materials and glasses offer a paradigm where disorder in the
arrangements of particles plays a fundamental role in determining the
energy landscape, and thereby their stability, response and elasticity
properties. Gradually introducing disorder into athermal crystalline
packings can be used to build a relation between the well-established
physics of crystals and that of amorphous solids. Such studies can
also reveal interesting phenomena peculiar to athermal systems such as
hidden order-disorder transitions. In this talk I will outline the
development of exact theoretical techniques which can be used to
characterize fluctuations in positions, forces and interaction
energies in near-crystalline athermal systems, which offer a route
towards understanding the emergent elasticity properties of ubiquitous
amorphous solids.