Thermodynamics and phase transitions in dissipative and active Morse chains
Abstract
We study the evolution of a simple one-dimensional chain of N=4 particles with Morse interactions and periodic boundary conditions which are imbedded into a heat bath creating dissipation and noise. The investigation is concentrated on thermodynamic properties for equilibrium, near-equilibrium and far-equilibrium conditions. For the thermodynamic equilibrium, created by white noise and passive friction obeying Einstein's fluctuation dissipation relation, we find a standard phase diagram. By applying active friction forces the system is driven to stationary non-equilibrium states, creating conditions where various self-sustained oscillations are excited. Thermodynamic quantities like energy, pressure and entropy are calculated near equilibrium, around a critical distance from equilibrium and far from equilibrium. We observe maximal order (minimum entropy) in certain region of the noise temperature, a phenomenon which is reminiscent of stochastic resonance. With increasing distance from equilibrium new "phases" corresponding to the existence of several attractors of the dynamical stem appear.
- Publication:
-
European Physical Journal B
- Pub Date:
- April 2005
- DOI:
- 10.1140/epjb/e2005-00151-2
- Bibcode:
- 2005EPJB...44..509C
- Keywords:
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- Entropy;
- Stochastic Resonance;
- Thermodynamic Quantity;
- Critical Distance;
- Heat Bath