Simulations of electric-field-induced turbulence and negative viscosity in conductive nematic liquid crystals
Phys. Rev. E 112, 065406 – Published 1 December, 2025
DOI: https://doi.org/10.1103/lf14-8dhh
Abstract
Experiments using a rotational rheometer have demonstrated that the apparent viscosity becomes negative under the electric-field-induced turbulent state of conductive nematic liquid crystals [Orihara et al., Phys. Rev. E 99, 012701 (2019); F. Kobayashi et al., Phys. Rev. E 101, 022702 (2020)]. When the upper rotating plate of the rheometer is left free, spontaneous rotation—that is, spontaneous shear flow—has also been observed. In this study, we reproduce these phenomena through three-dimensional simulations based on continuum theory. The simulations reveal characteristic velocity, director, and stress fields in the negative-viscosity state. Furthermore, they clarify the interplay between topological defects (disclinations) and space charges which drive the turbulence.
