Anankeon Theory and Viscosity of Liquids: a Toy Model | Dr. Jean V. Bellissard (Georgia Institute of Technology, Atlanta, GA; Westfälische Wilhelms-Universität, Münster, Germany)

Anankeon Theory and Viscosity of Liquids: a Toy Model

The behavior of the viscosity of liquid near the liquid-solid transition, which can change by 15 orders of magnitude within few degrees of temperature change, has long been considered as a deep and unsolved problem. 40 years of experimental datas and computer simulations have slowly revealed what are the main degrees of freedom to be considered. While phonons dominate in the solid phase, anankeons dominate the liquid phase. The complexity of liquids is miraculously transformed into a free gas of anankeons at least at high temperature, explaining the saturation of the heat capacity. At lower temperature, the competition between phonons and anankeons may explains the change in the behavior of the viscosity. We offer a simplistic model, based on these principles, showing how such a mechanism may work. This model introduces a new parameter that permits to understand the difference between strong and fragile liquids and predicts the existence of a crossover temperature below which the phonons strongly slow down the chaotic behavior of anankeons resulting in a tremendous increase of the viscosity.