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Active Brownian particles: entropy production and fluctuation response.
1Indian Institute of Technology Hyderabad, Yeddumailaram 502205, Andhra Pradesh, India.
Physical Review. E, Statistical, Nonlinear, and Soft Matter Physics
|September 13, 2014
Summary
Active Brownian particles generate entropy in steady states, violating detailed balance. Molecular dynamics simulations confirm fluctuation theorems for entropy production and a modified fluctuation-dissipation relation.
Area of Science:
- Statistical mechanics
- Soft matter physics
- Non-equilibrium thermodynamics
Background:
- The Rayleigh-Helmholtz model describes active Brownian particles with velocity-dependent forces.
- Non-equilibrium systems can break detailed balance, leading to entropy production.
- Understanding entropy production is crucial for characterizing active matter dynamics.
Purpose of the Study:
- To investigate entropy production in active Brownian particles under external potentials.
- To verify fluctuation theorems for entropy production in these systems.
- To examine the steady-state response function and its relation to dissipation.
Main Methods:
- Molecular dynamics simulations were employed to model active Brownian particles.
- The simulations analyzed systems with external trapping potentials and constant forces.
- Probability distributions of entropy production were calculated.
Main Results:
- Steady states of active Brownian particles were shown to break detailed balance and produce net entropy.
- The obtained probability distributions of entropy production obey fluctuation theorems.
- A modified fluctuation-dissipation relation was observed for the steady-state response function.
Conclusions:
- Active Brownian particles in non-equilibrium steady states exhibit predictable entropy production behavior.
- Fluctuation theorems provide a robust framework for analyzing entropy production in these systems.
- The modified fluctuation-dissipation relation offers new insights into the response of active matter.
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