Arrested dynamics of the dipolar hard sphere model

Area of Science:

• Physics
• Soft Matter Physics
• Computational Physics

Background:

• Dynamical arrest transitions are crucial phenomena in condensed matter.
• Understanding these transitions in dipolar fluids provides insights into complex fluid behavior.

Purpose of the Study:

• To investigate dynamical arrest transitions in a model dipolar fluid.
• To characterize the coupled translational and orientational dynamics across various concentrations and temperatures.

Main Methods:

• Molecular dynamics simulations were employed to model N rigid spheres with a truncated dipole-dipole potential.
• Theoretical calculations using self-consistent generalized Langevin equation theory were used for comparison.

Main Results:

• Three distinct dynamical arrest scenarios were identified.
• At low/intermediate concentrations, translational and orientational dynamics arrest simultaneously upon cooling.
• At high concentrations, translational dynamics arrest (glass transition), while orientations may remain ergodic, leading to partially arrested states.

Conclusions:

• The study provides a comprehensive description of dynamical arrest transitions in dipolar fluids.
• An arrested states diagram was developed, offering a generic picture of glass transitions in such systems.