Emergence of rigidity in crystals and glasses

by Prof. Grzegorz Szamel (Chemistry Department of Chemistry, Colorado State, USA University)

Monday 18 Jun 2012, 15:00 → 17:00 Europe/Rome

Aula Rasetti (Dipartiemnto di Fisica - Ed. G. Marconi)

I will start with a review of an earlier, microscopic study of ideal elasticity of crystalline solids. This work started with the recognition that the standard approach to crystals' elasticity misses one slow mode allowed by a phenomenological theory. We proposed a microscopic expression for a displacement field and showed that broken translational symmetry implies that the displacement field exhibits long-range correlations. We derived the non-dissipative hydrodynamic equations that include all the slow modes allowed by the phenomenological theory. In a recent work we analyzed amorphous solids (glasses). We showed that, like in crystals, breaking of translational symmetry implies the existence of long-range correlations and rigidity. We derived and evaluated a new microscopic expression for the glass shear modulus.