A Monte Carlo Simulation of a Twisted Nematic Liquid Crystal Display

Abstract

We present a Monte Carlo simulation of a model of a twisted nematic display on a lattice starting from purely microscopic interactions. We visualize the simulated display calculating optical textures under crossed polarizers corresponding to the Monte Carlo microscopic configurations. We also investigate the orientational order and the molecular organizations in the different regions of the lattice, introducing and calculating suitable order parameters.

Computer Simulations of Nematic Displays

“…The nematic ordering can be quantified by looking at the standard order parameter P 2 λ , obtained from the largest eigenvalue of the ordering matrix [7]. This quantity can be calculated also across the sample to investigate how the boundary layers, mimicking the effect of the aligning cell surfaces, influence the liquid crystal inside the lattice in the regions where the field is active or not [4].…”

“…For the TN display we have found useful to calculate at each layer of the sample an helical order parameter, < P 2 > H defined as [4]:…”

“…The aligned surfaces of the display are simulated by imposing a fixed orientation to the spins belonging to the layers at the top and at the bottom of the cell [4,5]. Periodic boundary conditions are instead employed around the other four faces of the simulation box to reduce the size effects.…”

“…Liq. Cryst., 360, 119-129 (2001) performed Monte Carlo simulations of a Twisted nematic [2] and a in-plane switching effect [3] displays by using a simple lattice spin model [4,5]. Here we briefly summarize the method and present some new results for the in-plane switching display.…”

Liquid Crystal Lattice Models on Quadrics Supercomputers

“…5 { 7 Moreover, apart from basic research, the large number of spins permits to tackle computer simulations of certain technologically relevant systems, such as LC displays. 16 In this case investigating the model in the presence of external elds of dierent t ype and intensity is important. The availability o f p o w erful computers is then essential for the aims mentioned above and here we wish to present the implementation of a MC code on a Quadrics and some tests and examples.…”