Spatially periodic and kinklike distortions in microsized nematic volumes.

Abstract

The purpose of this article is to describe the physical mechanism responsible for the appearance of both spatially periodic and kinklike distortions in a homogeneously aligned microsized nematic volume under the effect of crossed electric and magnetic fields. Numerical studies were carried out to describe the dynamic reorientation of the director^{'}s field in a thick liquid crystal (LC) cell (∼200μm) under the effect of a large electric field E (∼1.0V/μm) directed at an angle α close to a right angle to magnetic field B (∼7.0T). It is shown that under the effect of E directed at α∼89.96^{∘} to B, at least two scenarios of reorientation of the director field can be realized. First, in response to the suddenly applied electric field, spatially periodic patterns can appear in an initially uniformly aligned nematic domain. Second, when the same crossed external fields are applied at the smaller angle α∼88.81^{∘} to each other, the mode of uniform director reorientation is dominated. In the case when the electric field E≫E_{th} is applied orthogonally to both horizontal bounding surfaces of the LC cell and the magnetic field is turned off, in the microsized nematic volume the distortion in the form of the kinklike wave spreading normally to the horizontal bounding surfaces with the velocity in a few meters per second can be excited.