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Noise-induced transport in a rough ratchet potential
Debasish Mondal1, Pulak Kumar Ghosh, Deb Shankar Ray
1Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India. juniordebasish@gmail.com
The Journal of Chemical Physics
|February 26, 2009
Summary
Roughness in protein potentials significantly hinders diffusion current in a one-dimensional ratchet system. This study analyzes Brownian dynamics to understand how spatial roughness impacts current and efficiency under external driving forces.
Area of Science:
- Physics
- Physical Chemistry
- Biophysics
Background:
- Hierarchical structures in proteins can cause spatial roughness in potentials.
- Understanding diffusion in such potentials is crucial for molecular dynamics.
Purpose of the Study:
- To extend Zwanzig's diffusion model to overdamped Brownian dynamics in a rough, periodic ratchet potential.
- To analyze the impact of spatial roughness and external driving forces on system current and efficiency.
Main Methods:
- Developed a theoretical model for effective current in a one-dimensional rough ratchet potential.
- Investigated variations in current and efficiency with respect to roughness amplitude and nonthermal driving force.
- Corroborated analytical findings with detailed numerical simulations.
Main Results:
- Derived a general expression for the effective current at steady state.
- Demonstrated that spatial roughness significantly hinders the diffusion current.
- Quantified the influence of roughness amplitude and external driving force on current and efficiency.
Conclusions:
- Spatial roughness in protein-like potentials acts as a significant impediment to diffusion current.
- The findings provide insights into controlling current in molecular systems, potentially for applications like laser-switched molecular wires.
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