Topological phases and curvature-driven pattern formation in cholesteric shells. Issue 10 (27th February 2023)

• Record Type: Journal Article
• Authors: Negro, G.; Carenza, L. N.; Gonnella, G.; Marenduzzo, D.; Orlandini, E.
• Is Part Of: Soft matter. Volume 19:Issue 10(2023)
• Page Start: 1987
• Page End: 2000
• Publication Date: 2023-02-27
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/d2sm01347a
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : We study the phase behaviour of thin shells of cholesteric liquid crystal with spherical, ellipsoidal and toroidal shape, where the interplay between geometry, topology and chirality contributes to the development of blue phases. Abstract : We study the phase behaviour of cholesteric liquid crystal shells with different geometries. We compare the cases of tangential anchoring and no anchoring at the surface, focussing on the former case, which leads to a competition between the intrinsic tendency of the cholesteric to twist and the anchoring free energy which suppresses it. We then characterise the topological phases arising close to the isotropic–cholesteric transition. These typically consist of quasi-crystalline or amorphous tessellations of the surface by half-skyrmions, which are stable at lower and larger shell sizes, respectively. For ellipsoidal shells, defects in the tessellation couple to a local curvature, and according to the shell size, they either migrate to the poles or distribute uniformly on the surface. For toroidal shells, the variations in the local curvature of the surface stabilise heterogeneous phases where cholesteric or isotropic patterns coexist with hexagonal lattices of half-skyrmions.