Coarsening Dynamics of Umbilical Defects in Inhomogeneous Medium

Light-matter interaction induces a shadow vortex

“…Figure 2 element code with adaptive spatial and temporal steps, and a simulation box of dimensions 100 × 100 with Neumann boundary condition. Hence, model (4) adequately describes the observed dynamics of light-matter interaction in a liquidcrystal light cell with a photosensitive wall [6,7].…”

“…Note that the defects observed in this context are strongly dissipative, compared to those observed in magnetic systems, superfluids, superconductors, and Bose-Einstein condensates. Recently, by exploiting reorientational nonlinearities in the nematic liquid-crystal layer of an optically addressable liquid-crystal cell, the so-called liquid-crystal light valve (LCLV), it has been shown that spontaneous, stable matter vortices can be induced at the chosen location [6,7]. This is accomplished by sending light beams onto a homeotropic nematic liquid-crystal cell subjected to a voltage with a photosensitive wall.…”

“…Illuminating the liquid-crystal light valve with a Gaussian beam induces a voltage drop with a bell-shaped profile across the liquid-crystal layer, and higher in the center of the illuminated area. The electric field within the sample takes the form [7]…”

“…Considering the intensity of the light beam as small enough and close to the Fréedericksz transition, one can use the following ansatz for the amplitude of the critical spatial mode [7]:…”

“…Introducing the above ansatz in the director equation, integrating in the z coordinate over the sample thickness, and considering the complex amplitude A ≡ (u + iw), after straightforward calculations one obtains the forced Ginzburg-Landau equation [6,7],…”