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Straight round the twist: frustration and chirality in smectics-A
Elisabetta A Matsumoto1, Randall D Kamien2, Gareth P Alexander3
1School of Physics, Georgia Institute of Technology, 837 State Street, Atlanta, GA 30309, USA.
Interface Focus
|June 21, 2017
Summary
Frustration in chiral smectic liquid crystals can lead to complex defect textures. Highly chiral systems favor a hierarchical helical nanofilament phase over the standard twist grain boundary phase.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Liquid Crystal Physics
Background:
- Frustration in condensed matter systems drives order and complexity.
- In smectic liquid crystals, frustration between chirality and layer spacing creates defect-rich textures.
- The twist grain boundary (TGB) phase is typically the ground state for chiral type II smectics.
Purpose of the Study:
- To investigate various ground states of the chiral Landau-de Gennes free energy in smectic liquid crystals.
- To understand the influence of high chirality on phase stability.
Main Methods:
- Theoretical study of the chiral Landau-de Gennes free energy.
- Analysis of different ground states and their stability.
Main Results:
- The standard theory predicts the TGB phase as the ground state for chiral type II smectics.
- For highly chiral systems, the hierarchical helical nanofilament (HHNF) phase emerges.
- The HHNF phase is found to be stable and can supersede the TGB phase in highly chiral regimes.
Conclusions:
- Chirality plays a critical role in determining the ground state of smectic liquid crystals.
- The hierarchical helical nanofilament phase represents a stable alternative ground state in highly chiral smectics.
- This finding expands our understanding of defect formation and phase behavior in chiral liquid crystals.
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