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Electric field-induced acoustic-optic mode coupling in an anticlinic liquid crystal
1Department of Physics, Case Western Reserve University, Cleveland, Ohio 44106, USA.
Summary
A dc electric field coupled acoustic and optic Goldstone modes in anticlinic liquid crystals. This coupling increased the relaxation time of the acousticlike eigenmode, allowing for elastic constant estimation.
Area of Science:
- Condensed matter physics
- Liquid crystal physics
Background:
- Anticlinic liquid crystals exhibit unique electro-optic properties.
- Goldstone modes are collective excitations in liquid crystals.
Purpose of the Study:
- To investigate the effect of a dc electric field on anticlinic liquid crystals.
- To study the coupling between acoustic and optic Goldstone modes.
- To estimate elastic constants using relaxation time measurements.
Main Methods:
- Application of a dc electric field perpendicular to the tilt plane.
- Quasielastic light scattering measurements.
- Analysis of relaxation times of eigenmodes.
Main Results:
- A dc electric field couples acoustic and optic Goldstone modes.
- The relaxation time of the acousticlike eigenmode (tau(beta)) increases due to this coupling.
- Elastic constants can be estimated from the observed relaxation time data.
Conclusions:
- The study demonstrates field-induced coupling of Goldstone modes in anticlinic liquid crystals.
- Relaxation time measurements provide a method for determining elastic constants.
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