Fine structure of the topological defect cores studied for disclinations in lyotropic chromonic liquid crystals
| Autor: | Oleg D. Lavrentovich, Sergij V. Shiyanovskii, Shuang Zhou, Heung-Shik Park |
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| Rok vydání: | 2016 |
| Předmět: |
Physics
Multidisciplinary Condensed matter physics Science General Physics and Astronomy 02 engineering and technology General Chemistry 021001 nanoscience & nanotechnology 01 natural sciences General Biochemistry Genetics and Molecular Biology Symmetry (physics) Article Topological defect Characterization (materials science) Amplitude Liquid crystal Phase (matter) 0103 physical sciences Lyotropic Chromonic 010306 general physics 0210 nano-technology |
| Zdroj: | Nature Communications Nature Communications, Vol 8, Iss 1, Pp 1-7 (2017) |
| ISSN: | 2041-1723 |
| Popis: | The detailed structure of singularities of ordered field represents a fundamental problem in diverse areas of physics. At the defect cores, the deformations are so strong that the system explores states with symmetry different from that of an undistorted material. These regions are difficult to explore experimentally as their spatial extension is very small, a few molecular lengths in the condensed matter. Here we explore the cores of disclinations in the so-called chromonic nematics that extend over macroscopic length scales accessible for optical characterization. We demonstrate that the amplitude S and the phase (the director) of the order parameter vary along both the radial and azimuthal directions, in contrast to the classic models in which S varies only with the distance from the centre and depends only on the azimuthal coordinate. This unexpected core structure is explained by a strong coupling of the phase and amplitude of the order parameter in the free energy. Topological defects play important roles in determining material properties, whilst their core regions remain unexplored due to strongly distorted structures. Zhou et al. take advantage of extended core regions in a chromonic liquid crystal and show both a radial and azimuthal dependent director and scalar order parameter. |
| Databáze: | OpenAIRE |
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