The influence of flow on symmetric and asymmetric splay state relaxations

Abstract

Abstract We present a detailed discussion of the relaxation of splayed states in untwisted devices — the asymmetric H state (Ha), and the recently observed symmetric H state (Hs). Experimental evidence suggests that the Hs does not experience the optical bounce due to induced backflow usually associated with splay state relaxation. A dynamic model using Leslie–Eriksen–Parodi theory has been developed, and is used to model the flow within the device during switching. We show that there is no backflow during Hs relaxation, and that the flow profile is similar to that present during relaxation of the V state (the state used for pi‐cell operation). This flow enhances the switching of the Hs, leading to a faster relaxation than might be expected. The influence of the different viscosity parameters is examined in detail, and a comparison between the experimental and simulated results is given. Acknowledgements The authors would like to thank Merck UK, the COMIT Faraday Partership and the EPSRC for their financial support.