Propagation gap for shear waves in binary liquids: Analytical and simulation study.

Area of Science:

• Condensed Matter Physics
• Statistical Mechanics
• Liquid State Theory

Background:

• Transverse collective excitations are fundamental to understanding liquid dynamics.
• Binary liquid mixtures exhibit complex behaviors influenced by component properties.
• Lennard-Jones potentials model interatomic interactions in simple and mixed systems.

Purpose of the Study:

• Investigate transverse collective excitations in Lennard-Jones binary liquid mixtures.
• Analyze the effect of varying mass ratios on shear waves and transverse optic modes.
• Develop and solve a dynamic model for transverse dynamics in binary liquids.

Main Methods:

• Simulations of 50-50 and 80-20 Lennard-Jones binary liquid mixtures.
• Analysis of transverse collective excitations at fixed numerical densities.
• Analytical solution of a four-variable dynamic model in the long-wavelength limit.

Main Results:

• Increasing mass ratio (R) enhances the frequency difference between shear waves and transverse optic modes.
• The propagation gap width for shear waves increases with the mass ratio.
• An analytical equation for the shear wave propagation gap in binary liquids was derived.

Conclusions:

• Mass ratio is a critical parameter governing transverse dynamics in binary liquids.
• The derived model provides insights into shear wave propagation gaps.
• Findings contribute to the understanding of collective excitations in multi-component liquids.