Helicoids in chiral liquid crystals under external fields

Waveguiding by helicoids in confined chiral nematics

“…In this work, we study the scattering of a circularly polarized plane wave with two of these new configurations, called π-helicoids and 2π-helicoids, recently described in [19].…”

“…This phenomenon is emphasized if the wavelength of the incoming wave λ ∼ p, where p, called pitch, in our case can be considered as the effective size of the helicoid. We shall use the results from [19], in order to describe the dependence of the scattering process on the inner chiral forces and external electric/magnetic uniform fields. Thus, once tuned the wavelength of the incoming wave with the size of the textures, the external field can be used to switch beetween the different helicoidal phases with response times of the order of few hundreds of µs or less [25][26][27][28].…”

“…At the bounding surfaces, we impose strong homeotropic anchoring conditions, that is n x, y, z = ± L 2 = ẑ. We want to study the interaction of the light with single helicoids as those introduced in the previous section and decribed in [19]. We first note that for helicoids the director in (2.1) specializes…”

Quantum particle motion on the surface of a helicoid in the presence of harmonic oscillator

“…Some particular geometries are interesting since they occur in nature. The helicoidal geometry naturally occurs in Chiral Liquid Crystals [37], in macromolecules of DNA [38,39] and in fibril structures in animals and plants [40]. The helicoidal geometry has been studied in several scenarios in physics, like in the context of branes and black-hole physics [41], for example.…”

Non-uniform localised distortions in generalised elasticity for liquid crystals

“…All of them show interesting new properties and phase transitions when frustrated by geometric confinement and/or external fields [1][2][3][5][6][7]. In particular, in recent years it has been demonstrated that chiral nematics can be host for a pletora of new topological and non topological solitonic structures, i. e. skyrmions, helicoids, merons and hopfions [8][9][10][11][12][13]. Furthermore, skyrmion clusters with mutually orthogonal orientations of the constituent isolated skyrmions have been observed and studied in frustrated chiral liquid crystals [14,15].…”