M. Copic et Na. Clark, THEORY OF ORIENTATIONAL MODES AT A NEMATIC SOLID INTERFACE WHEN DO SURFACE-MODES APPEAR, Liquid crystals, 17(2), 1994, pp. 149-155
Orientational modes at a solid-nematic interface with Rapini-Papoular
boundary conditions are analysed in the framework of continuum nematod
ynamics, including the coupling of the director and fluid velocity. In
the case of planar orientation, a surface mode appears in addition to
the ordinary bulk modes, if the coupling between the director and flu
id velocity, governed by the Leslie coefficient mu2, is large enough.
The dispersion relation for the surface mode exhibits two distinctive
regimes as mu2 increases. In a realistic situation, the relaxation rat
e of the surface mode is several times slower than that of the corresp
onding bulk mode.