STRUCTURE AND DYNAMICS OF SOLITONS IN A NEMATIC LIQUID-CRYSTAL IN A ROTATING MAGNETIC-FIELD

We study the structure and speed of movement of dynamic solitons in a thin layer of nematic liquid crystal, with homeotropic boundary condit ions, in a rotating magnetic field. Based on numerical integration of the equations of motion, we find that the soliton must be described as a two-dimensional object with unconstrained director motion. From som e qualitative features of the soliton structure seen in our numerical results, we are able to deduce an approximate analytic theory of the p hysics of the soliton structure and dynamics that accounts accurately for the observations. The basic elements of this picture are a tilted plane in which the director rotates as the soliton passes a point, wit h the tilt angle of the plane being dictated by a second Freedericksz transition within the soliton.