Nanomechanics of order reconstruction in nematic liquid crystals

We employ a continuum model to compute both torque and force transmitted through a thin twist cell filled with a nematic liquid crystal and bounded by flat plates with anchorings at right angles. The transmitted torque vanishes at the order reconstruction threshold when the cell thickness is comparable with the biaxial coherence length. At the same point, the force diagram exhibits an angular point which disappears above a critical twist mismatch. Both torque and force diagrams against the cell's thickness fail to be monotonic when the total twist is near pi/2.