Electric field-induced fast nematic order dynamics

A strong electric field is able to induce transient and/or local biaxial states within a nematic calamitic phase, andthe resultant nematic texture can be identified by the Landau–de Gennes Q-tensor theory. In this study we presenta numerical Q-tensor model implemented with an adaptive moving-mesh finite element method, and this is ableto describe the nematic order dynamics within a one-dimensional π-cell under the action of rapid electric pulsesof different amplitudes. The proposed technique concentrates the grid points within regions of large ∇Q, keepingthe total number of nodes in the domain constant in order to avoid waste of computational effort in areas wherespatial order variability is low. Both the nematic order and the electric current flowing across the cell are stronglydependent on the amplitude of the applied electric field. The evolution of biaxiality allows not only monostableelastic distortions to be described, but also textural transitions between nematic states with different topologies.