First-order phase transition in a model of self-propelled particles with variable angular range of interaction

Area of Science:

• Complex Systems
• Statistical Physics
• Nonlinear Dynamics

Background:

• The Vicsek model describes collective motion in systems of self-propelled particles.
• Understanding factors influencing ordered motion is crucial for complex systems research.

Purpose of the Study:

• To investigate the impact of directional interactions on collective motion in a modified Vicsek model.
• To analyze the role of the 'view angle' in phase transitions of self-propelled particles.

Main Methods:

• Monte Carlo simulations were employed to model particle dynamics.
• A modified Vicsek model with a sector-based interaction neighborhood was utilized.
• The 'view angle' parameter was systematically varied to observe its effects.

Main Results:

• Ordered collective motion was observed to persist even at small 'view angles'.
• A first-order phase transition to a disordered state occurred at a critical 'view angle'.
• Reducing the 'view angle' significantly increased the system's order.

Conclusions:

• Directionality of particle interactions is a key factor in phase transition behavior.
• The 'view angle' critically influences the transition from ordered to disordered collective motion.
• The modified Vicsek model provides insights into emergent order in systems with limited interaction ranges.