Related Experiment Video
Updated: May 29, 2026

An Analog Macroscopic Technique for Studying Molecular Hydrodynamic Processes in Dense Gases and Liquids
Published on: December 4, 2017
Tagged-particle motion in glassy systems under shear: Comparison of mode coupling theory and Brownian dynamics
1Fachbereich Physik, Universität Konstanz, 78457 Konstanz, Germany. kruegerm@mit.edu
Abstract:
We study the dynamics of a tagged particle in a glassy system under shear. The recently developed integration through transients approach, based on mode coupling theory, is continued to arrive at the equations for the tagged-particle correlators and the mean squared displacements. The equations are solved numerically for a two-dimensional system, including a nonlinear stability analysis of the glass solution, the so called β-analysis. We perform Brownian Dynamics simulations in 2D and compare with theory. After switch on, transient glassy correlation functions show strong fingerprints of the stress overshoot scenario, including, additionally to previously studied superexponential decay, a shoulder-like slowing down after the overshoot. We also find a new type of Taylor dispersion in glassy states which has intriguing similarity to the known low-density case. The theory qualitatively captures most features of the simulations with quantitative deviations concerning the shear-induced time scales. We attribute these deviations to an underestimation of the overshoot scenario in the theory.
Related Concept Videos
The Fluid Mosaic Model
First Law: Particles in Two-dimensional Equilibrium
Newton's first law tells us about the...
Basic Postulates of Kinetic Molecular Theory: Particle Size, Energy, and Collision
The de Broglie Wavelength
Kinetic Theory of an Ideal Gas
The number of molecules in one mole is called Avogadro's number...
First Law: Particles in One-dimensional Equilibrium

