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Published on: September 26, 2014
Active-absorbing-state phase transition beyond directed percolation: a class of exactly solvable models
1Theoretical Condensed Matter Physics Division, Saha Institute of Nuclear Physics, 1/AF Bidhan Nagar, Kolkata 700064, India. urna.basu@saha.ac.in
Summary
This study models hardcore particles on a lattice, revealing an active-absorbing-state phase transition. Below half particle density, active sites and survival vanish, indicating a new universality class.
Area of Science:
- Statistical Mechanics
- Condensed Matter Physics
- Complex Systems
Background:
- Active-absorbing-state phase transitions are crucial in nonequilibrium systems.
- Understanding particle dynamics on lattices informs material science and statistical physics.
- Previous models often lack analytical solutions for critical exponents.
Purpose of the Study:
- To introduce and solve a novel model of hardcore particles on a 1D lattice.
- To investigate the active-absorbing-state phase transition at finite density.
- To determine the universality class of the observed nonequilibrium phase transition.
Main Methods:
- Development of a stochastic hopping model for hardcore particles.
- Exact analytical solution using the matrix product ansatz.
- Calculation of critical exponents and spatial correlations.
Main Results:
- The model exhibits an active-absorbing-state phase transition at finite particle density.
- Density of active sites and survival probability vanish below half particle density.
- Critical exponents and spatial correlations were determined exactly.
Conclusions:
- The model demonstrates a new universality class for nonequilibrium phase transitions.
- This class differs from the generic directed percolation universality class.
- The matrix product ansatz provides an exact analytical framework for such systems.
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