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Work fluctuations in a nonlinear micromechanical oscillator driven far from thermal equilibrium
P Zhou1, X Dong1, C Stambaugh2
1Department of Physics, the Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China.
Summary
We studied fluctuation theorems in a driven micromechanical oscillator. In nonlinear regimes, work fluctuations show unique behavior, differing from conventional theories.
Area of Science:
- Physics
- Nonlinear Dynamics
- Statistical Mechanics
Background:
- Fluctuation relations are key in nonequilibrium statistical mechanics.
- Conventional fluctuation theorems apply to systems in the linear regime.
- Understanding driven systems is crucial for thermodynamics.
Purpose of the Study:
- To investigate fluctuation relations in a periodically driven micromechanical torsional oscillator.
- To explore deviations from conventional fluctuation theorems in nonlinear regimes.
- To analyze the impact of bistability on work fluctuations.
Main Methods:
- Experimental setup: periodically driven micromechanical torsional oscillator.
- Regime exploration: linear (weak modulation) and nonlinear (strong modulation).
- Data analysis: work variance, mean work, and dependence on driving frequency and noise intensity.
Main Results:
- Linear regime: verified conventional fluctuation theorems (constant work variance/mean work ratio).
- Nonlinear regime: observed coexistence of two nonequilibrium oscillation states.
- Work variance peaked at a specific driving frequency due to interstate transitions.
- Work fluctuations showed exponential dependence on inverse noise intensity.
Conclusions:
- Data align with theories predicting distinct behaviors in bistable driven systems.
- Findings highlight the limitations of conventional fluctuation theorems in nonlinear, nonequilibrium scenarios.
- The study provides experimental evidence for novel fluctuation behaviors in driven bistable systems.