Theory of the Stripe Phase in Bend-Fréedericksz-Geometry Nematic Films

An outstanding problem in the physics of nematic films is the stripe phase which appears in the bend Fréedericksz geometry at temperatures slightly above that of the nematic to smectic-$A$ phase transition in a sufficiently strong magnetic field. It is argued, by use of linear stability analysis, that in fact two transitions occur: the usual Fréedericksz transition to a uniformly distorted state, followed by a second transition to a stripe phase at a slightly higher field. Qualitative agreement is found between experimental results and theoretical predictions.