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Published on: August 21, 2018
Driven front propagation in 1D spatially periodic media
F Haudin1, R G Elías, R G Rojas
1INLN, Université de Nice Sophia-Antipolis, CNRS, 06560 Valbonne, France.
Physical Review Letters
|October 2, 2009
Summary
Researchers investigated front propagation in periodic media using optical feedback in liquid crystals. They observed pinning and oscillatory motion, with findings supported by numerical simulations and a theoretical model.
Area of Science:
- Physics
- Materials Science
- Nonlinear Dynamics
Background:
- Front propagation in spatially periodic media is crucial for understanding pattern formation and instabilities.
- Optical feedback systems offer tunable control over dynamic processes in materials.
Purpose of the Study:
- To investigate front propagation dynamics in a one-dimensional spatially periodic medium under external forcing.
- To explore the effects of optical forcing on front behavior, specifically pinning and oscillations.
- To validate experimental observations with numerical simulations and a theoretical model.
Main Methods:
- Experimental setup using a one-dimensional nematic liquid crystal cell with optical feedback and a spatially amplitude-modulated beam.
- Systematic variation of forcing parameters to observe changes in front dynamics.
- Numerical simulations of the average liquid crystal tilt angle to confirm experimental results.
- Development of a spatially forced dissipative varphi;{4} model to explain observed phenomena.
Main Results:
- Observed pinning effect of the front propagation under specific forcing conditions.
- Documented oscillatory motion of the front as a function of forcing parameters.
- Numerical simulations successfully reproduced the experimentally observed pinning and oscillatory behaviors.
- The derived varphi;{4} model qualitatively accounted for the complex front dynamics.
Conclusions:
- The study demonstrates controllable front propagation in periodic media via optical forcing.
- The interplay between spatial periodicity, forcing, and nonlinear dynamics leads to rich phenomena like pinning and oscillations.
- The developed theoretical model provides a framework for understanding forced front propagation in such systems.
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