Jamming at zero temperature, zero friction, and finite applied shear stress

Area of Science:

• Soft matter physics
• Rheology
• Statistical mechanics

Background:

• Shear stress, analogous to temperature, drives particle motion and influences phase transitions in materials.
• Understanding the jamming transition is crucial for predicting material behavior from fluid to solid states.

Purpose of the Study:

• To investigate the impact of shear stress on the jamming transition.
• To characterize the nature of the jamming transition under varying shear stress conditions.

Main Methods:

• Analysis of particle dynamics under applied shear stress.
• Examination of system behavior approaching the jamming transition from both fluid and solid phases.
• Characterization of hysteresis and transition order.

Main Results:

• Finite shear stress introduces hysteresis in the jamming transition, allowing for both flowing and jammed states within a parameter range.
• The jamming transition at low shear stress exhibits characteristics of a mixed first-order and second-order transition.
• This low-stress transition shares similarities with the glass transition observed in thermal systems, marked by discontinuities in time-dependent quantities like the self-intermediate scattering function.

Conclusions:

• Shear stress is a critical parameter that fundamentally alters the nature of the jamming transition.
• The presence of hysteresis at finite shear stress indicates a history-dependent behavior in soft matter systems.
• The findings provide insights into the fundamental mechanisms governing the transition from fluid to disordered solid states.