Surface stabilized topological solitons in nematic liquid crystals

Nys, Inge (avtor), Berteloot, Brecht (avtor), Poy, Guilhem (avtor)

Photo-alignment is a versatile tool to pattern the alignment at the confining substrates in a liquid crystal (LC) cell. Arbitrary alignment patterns can be created by using projection with a spatial light modulator (SLM) for the illumination. We demonstrate that a careful design of the alignment patterns allows the stabilization of topological solitons in nematic liquid crystal (NLC) cells, without the need for chirality or strong confinement. The created LC configurations are stabilized by the anchoring conditions imposed at the substrates. The photo-aligned background at both substrates is uniformly planar aligned, and ring-shaped regions with a 180° azimuthal rotation are patterned with an opposite sense of rotation at the top and bottom substrate. A disclination-free structure containing a closed ring of vertically oriented directors is formed when the patterned rings at the top and bottom substrate overlap. Thanks to the topological stability, a vertical director orientation in the bulk is observed even when the centra of both patterned rings are shifted over relatively large distances. The combination of numerical simulations with experimental measurements allows identification of the 3D director configuration in the bulk. A finite element (FE) Q-tensor simulation model is applied to find the equilibrium director configuration and optical simulations are used to confirm the correspondence with experimental microscopy measurements. The created LC configurations offer opportunities in the field of optical devices, light guiding and switching, particle trapping and studies of topological LC structures.

• Jezik: Angleški jezik
• Ključne besede: nematic liquid crystals, topological solitons, optics
• Tipologija: 1.01 - Izvirni znanstveni članek
• Organizacija: FMF - Fakulteta za matematiko in fiziko
• Status publikacije: Objavljeno
• Različica publikacije: Objavljena publikacija
• Leto izida: 2020
• Št. strani: 17 str.
• Številčenje: Vol. 10, art. no. 840
• PID: 20.500.12556/RUL-124794
• UDK: 538.9
• ISSN pri članku: 2073-4352
• DOI: 10.3390/cryst10090840
• COBISS.SI-ID: 52294147
• Datum objave v RUL: 18.02.2021

Gradivo je del revije

• Naslov: Crystals
• Skrajšan naslov: Crystals
• Založnik: MDPI
• ISSN: 2073-4352
• COBISS.SI-ID: 36677893

Licence

• Licenca: CC BY 4.0, Creative Commons Priznanje avtorstva 4.0 Mednarodna
• Povezava: http://creativecommons.org/licenses/by/4.0/deed.sl
• Opis: To je standardna licenca Creative Commons, ki daje uporabnikom največ možnosti za nadaljnjo uporabo dela, pri čemer morajo navesti avtorja.
• Začetek licenciranja: 18.02.2021

Sekundarni jezik

• Jezik: Slovenski jezik
• Ključne besede: nematski tekoči kristali, topološki solitoni, optika

Projekti

• Financer: ARRS - Agencija za raziskovalno dejavnost Republike Slovenije
• Številka projekta: P1-0099
• Naslov: Fizika mehkih snovi, površin in nanostruktur

• Financer: EC - European Commission
• Program financ.: H2020
• Številka projekta: 834256
• Naslov: Interacting optical and topological solitons in frustrated cholesterics
• Akronim: OPTOSOL