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Generic two-phase coexistence, relaxation kinetics, and interface propagation in the quadratic contact process:
Xiaofang Guo1, Da-Jiang Liu, J W Evans
1Ames Laboratory, U.S. DOE and Departments of Physics & Astronomy and Mathematics, Iowa State University, Ames, Iowa 50011, USA.
Summary
The quadratic contact process, an adsorption-desorption model, exhibits two stable states: an active low-coverage state and a poisoned absorbing state. This phase coexistence is driven by adsorption rates and lattice structure.
Area of Science:
- Statistical Physics
- Complex Systems Modeling
- Surface Science
Background:
- The quadratic contact process is a key model in statistical physics for studying adsorption-desorption phenomena.
- Understanding phase transitions and steady states in lattice models is crucial for various scientific disciplines.
Purpose of the Study:
- To formulate and analyze the quadratic contact process as an adsorption-desorption model on a 2D lattice.
- To characterize the model's steady states, phase coexistence, and relaxation dynamics.
- To investigate the influence of spatial inhomogeneity on interface propagation.
Main Methods:
- Formulation of the quadratic contact process as a lattice-based adsorption-desorption model.
- Kinetic Monte Carlo simulations to assess model behavior.
- Analysis of spatially homogeneous and inhomogeneous systems.
Main Results:
- Identification of generic two-phase coexistence between an active steady state and a poisoned absorbing steady state.
- Characterization of relaxation kinetics, including rapid poisoning, nucleation-mediated poisoning, and bootstrap percolation-like dynamics.
- Detailed analysis of interface propagation in inhomogeneous systems, revealing orientation dependence.
Conclusions:
- The quadratic contact process exhibits stable coexistence of active and poisoned states, distinct from equilibrium phase separation.
- Lattice structure and adsorption rates significantly influence the system's dynamics and steady-state behavior.
- Spatial inhomogeneity leads to complex interface dynamics with orientation-dependent characteristics.
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