Dark solitons in liquid crystals with competing re-orientational and thermal nonlocal nonlinearities

Abstract

The properties of dark solitons in liquid crystals with competing nonlinearities are investigated by the model proposed by Jung. Under the condition of the rectangular response function, the relationship between the width of the dark soliton and the parameters of the medium is obtained by the variational method. It is found that the width of the dark solitons first decreases and then increases with the increment of the orientational nonlocality, the width of the soliton increases monotonously with the increase of the thermal nonlocality, and the width of the soliton decreases monotonously with the increase of the thermal nonlinearity coefficient. It is also found that the width of dark solitons is more sensitive to the orientational nonlocality than the other parameters. In addition, the width of the soliton increases monotonously with the grayness of the solitons. The analytical results are consistent with the numerical simulations that are obtained by the split-step Fourier algorithm.