Field Induced Memory Effects in Random Nematics

Abstract

We studied numerically external field induced memory effects in randomly perturbed nematic liquid crystals. Random anisotropy nematic-type lattice model was used. Theimpuritiesimposing orientational disorder were randomly spatially distributed with the concentrationpbelow the percolation threshold. Simulations were carried for finite temperatures, where we variedp, interaction strength between LC molecules, andimpuritiesand external fieldB. In the{B,T}plane we determined lines separating short range—quasi long range and quasi long range—long range order. Furthermore, crossover regime separating external field and random field dominated regime was estimated. We calculated remanent nematic ordering in samples atB=0as a function of the previously experienced external field strengthB.