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Dynamic Magneto-optic Coupling in a Ferromagnetic Nematic Liquid Crystal
Tilen Potisk1,2, Daniel Svenšek1, Helmut R Brand2
1Department of Physics, Faculty of Mathematics and Physics, University of Ljubljana, SI-1000 Ljubljana, Slovenia.
Physical Review Letters
|September 27, 2017
Summary
We found dynamic magneto-optic coupling in ferromagnetic nematic liquid, where liquid crystal and magnetic orders interact. This cross-coupling significantly impacts magneto-optic response, similar to rotational viscosity in pure liquid crystals.
Area of Science:
- Complex fluid hydrodynamics
- Magneto-optic phenomena
- Liquid crystal physics
Background:
- Hydrodynamics of complex fluids involve multiple order parameters and material constants.
- Ferromagnetic nematic liquids exhibit coupled liquid crystalline and magnetic order.
Purpose of the Study:
- To investigate the dynamics of magneto-optic response in a ferromagnetic nematic liquid.
- To understand the role of dissipative dynamic cross-coupling between nematic and magnetic order parameters.
Main Methods:
- Experimental investigation of magneto-optic response dynamics.
- Theoretical modeling using macroscopic theory.
- Fitting experimental data to macroscopic theory to determine cross-coupling coefficients.
Main Results:
- A unique example of dynamic magneto-optic coupling was observed.
- The magneto-optic response is significantly affected by cross-coupling between nematic and magnetic orders.
- The cross-coupling coefficient is comparable in magnitude to the rotational viscosity of pure liquid crystals.
Conclusions:
- Dissipative dynamic cross-coupling plays a crucial role in the hydrodynamics of ferromagnetic nematic liquids.
- The findings provide insights into the complex interplay between different order parameters in soft magnetic materials.
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