Elliptic shear applied to a homeotropically oriented nematic above theelectric bend Freedericks transition (FT) generates slow precession of thedirector. The character of the accompanying nonlinear waves changes fromdiffusive phase waves to dispersive ones exhibiting spirals and spatio-temporalchaos as the FT is approached from above. An exact solution of the flowalignment equations captures the observed precession and predicts its reversalfor non-flow aligning materials. The FT transforms into a Hopf bifurcationopening the way to understand the wave phenomena.
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