Confinement Reveals Hidden Splay-Bend Order in Twist-Bend Nematics
Fuente:
arXiv
Enregistré dans:
| Auteurs principaux: | , , |
|---|---|
| Format: | Preprint |
| Publié: |
2025
|
| Sujets: | |
| Accès en ligne: | |
| Tags: |
Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
|
| _version_ | 1866917334086582272 |
|---|---|
| author | Drzazga, Szymon Kubala, Piotr Longa, Lech |
| author_facet | Drzazga, Szymon Kubala, Piotr Longa, Lech |
| contents | Using extensive Monte Carlo (MC) and molecular dynamics (MD) simulations, we investigate how spatial confinement affects molecular organization within thin films of the nematic twist-bend ($\mathrm{N_{TB}}$) phase. Our simulations show that confinement markedly amplifies the otherwise elusive splay-bend order, primarily by suppressing the intrinsic three-dimensional heliconical structure characteristic of bulk $\mathrm{N_{TB}}$.
Remarkably, when the $\mathrm{N_{TB}}$ phase is confined between parallel walls imposing planar anchoring, and the bulk wave vector is oriented parallel to the walls, a smectic splay-bend ($\mathrm{S_{SB}}$) phase spontaneously emerges near the confining surfaces. This intermediate structure subsequently transforms into the bulk $\mathrm{N_{TB}}$ phase either directly via a smectic splay-bend-twist ($\mathrm{S_{SBT}}$) phase or through a sequence involving both the $\mathrm{S_{SBT}}$ and the nematic splay-bend-twist ($\mathrm{N_{SBT}}$) phases. Notably, the $\mathrm{N_{SBT}}$ phase becomes particularly pronounced as the molecular bend angle approaches its maximum attainable value in bulk $\mathrm{N_{TB}}$; this regime occurs in close proximity to the $\mathrm{N}\text{--}\mathrm{S_{A}}\text{--}\mathrm{S_{SB}}$ triple point on the bulk phase diagram.
Our findings reveal a compelling and intricate interplay among chirality, confinement, and molecular ordering, further evidenced by the calculated elementary director distortions. Crucially, this study opens promising avenues for experimental exploration: confined thin-film geometries serve as powerful model systems for revealing and characterizing novel nematic and smectic liquid-crystal phases that remain elusive in, or currently inaccessible to, bulk experiments. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2508_21655 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | Confinement Reveals Hidden Splay-Bend Order in Twist-Bend Nematics Drzazga, Szymon Kubala, Piotr Longa, Lech Soft Condensed Matter Using extensive Monte Carlo (MC) and molecular dynamics (MD) simulations, we investigate how spatial confinement affects molecular organization within thin films of the nematic twist-bend ($\mathrm{N_{TB}}$) phase. Our simulations show that confinement markedly amplifies the otherwise elusive splay-bend order, primarily by suppressing the intrinsic three-dimensional heliconical structure characteristic of bulk $\mathrm{N_{TB}}$. Remarkably, when the $\mathrm{N_{TB}}$ phase is confined between parallel walls imposing planar anchoring, and the bulk wave vector is oriented parallel to the walls, a smectic splay-bend ($\mathrm{S_{SB}}$) phase spontaneously emerges near the confining surfaces. This intermediate structure subsequently transforms into the bulk $\mathrm{N_{TB}}$ phase either directly via a smectic splay-bend-twist ($\mathrm{S_{SBT}}$) phase or through a sequence involving both the $\mathrm{S_{SBT}}$ and the nematic splay-bend-twist ($\mathrm{N_{SBT}}$) phases. Notably, the $\mathrm{N_{SBT}}$ phase becomes particularly pronounced as the molecular bend angle approaches its maximum attainable value in bulk $\mathrm{N_{TB}}$; this regime occurs in close proximity to the $\mathrm{N}\text{--}\mathrm{S_{A}}\text{--}\mathrm{S_{SB}}$ triple point on the bulk phase diagram. Our findings reveal a compelling and intricate interplay among chirality, confinement, and molecular ordering, further evidenced by the calculated elementary director distortions. Crucially, this study opens promising avenues for experimental exploration: confined thin-film geometries serve as powerful model systems for revealing and characterizing novel nematic and smectic liquid-crystal phases that remain elusive in, or currently inaccessible to, bulk experiments. |
| title | Confinement Reveals Hidden Splay-Bend Order in Twist-Bend Nematics |
| topic | Soft Condensed Matter |
| url | https://arxiv.org/abs/2508.21655 |