Three-state active lattice gas: A discrete Vicsek-like model with excluded volume

Area of Science:

• Physics
• Statistical Mechanics
• Soft Matter Physics

Background:

• Active matter systems exhibit complex emergent behaviors.
• Understanding phase transitions in discrete models is crucial for theoretical physics.

Purpose of the Study:

• To investigate spatial patterns and phase transitions in a discrete-space active matter model.
• To characterize the order-disorder transition at different densities and noise levels.

Main Methods:

• Monte Carlo simulations on a triangular lattice.
• Analysis of particle density, noise intensity, and spatial patterns.
• Characterization of phase transitions and critical exponents.

Main Results:

• Observed coexistence of condensed structures and low-density vapor.
• Condensed structures exhibit reduced particle mobility.
• Identified continuous and discontinuous order-disorder transitions based on density.

Conclusions:

• The model exhibits rich phase behavior, including ordered condensed phases and disordered states.
• Phase transition characteristics are density-dependent, mirroring Potts model behavior at full occupation.
• Low-density transitions show hysteresis and dependence on initial conditions.