Dynamical Properties of Cubatic Liquid Crystals


Dennison, M.1, Duncan, P.2 Wilson, M. 2 and Masters, A.1
1School of Chemical Engineering and Analytical Science, University of Manchester, United Kingdom; 2 Durham University, United Kingdom


The cubatic liquid crystalline phase is an exotic form of matter in which particles have no long range positional order but the orientations have a cubic symmetry, with particles preferentially forming stacks and pointing along the x-, y- and z- axes with equal probability. This phase was first observed in systems of truncated hard spheres. We have used molecular dynamics to study for the first time the dynamical properties of this phase, using a model system of rigid, square slabs formed from repulsive spheres.
We briefly present the form of the hydrodynamic equations for this phase, involving the coupling of the conserved variables to elastic fluctuations, and then show a selection of time correlation functions, clarifying the influence of the special symmetry of the phase on dynamical properties. We have also studied the effect of shearing the cubatic phase, finding that increasing the shear rate drives a phase transition to a nematic phase – a phase that is not stable at equilibrium. We present a preliminary phase diagram, showing the effects of shear.