Skyrmion tubes in achiral nematic liquid crystals

We analyze the interaction with uniform external fields of nematic liquid crystals within a recent generalized free energy posited by Virga and falling in the class of quartic functionals in the spatial gradients of the nematic director. We review some known interesting solutions, i.e., uniform heliconical structures, which correspond to the so-called twist-bend nematic phase and we also study the transition between this phase and the standard uniform nematic one. The twist-bend phase is further reproduced by three-dimensional simulations. Moreover, we find liquid crystal configurations, which closely resemble some novel, experimentally detected, structures called Skyrmion tubes. Skyrmion tubes are characterized by a localized cylindrically symmetric pattern surrounded by either twist-bend or uniform nematic phase. We study the equilibrium differential equations and find numerical solutions and analytical approximations.

Automated summary

In this study, we analyzed the interaction between nematic liquid crystals and uniform external fields using a generalized free energy proposed by Virga. We reviewed some interesting solutions, such as uniform heliconical structures corresponding to the twist-bend nematic phase, and studied the transition between this phase and the standard uniform nematic phase. We also found liquid crystal configurations that closely resemble experimentally detected Skyrmion tubes.