Quantifying memory: detection of focal conic domain rearrangement across a phase transition

Abstract

The behavior of topological defects near phase transition in liquid crystals has stimulated research in recent years, which has shown that a certain amount of “memory”' is retained when a defect characteristic of a liquid crystal phase turns into a defect belonging to a different phase. We aim to quantify this “memory effect” at the transition between smectic-A and nematic liquid crystal phases using focal conic domains in topographic confinement. These geometric defects, which spontaneously form in the smectic-A phase, disappear above the phase transition. However, we show that when the system is cooled back into the smectic phase, the defects tend to reform in their original location and that this behavior depends on the temperature at which they are heated, suggesting that the system retains temperature-dependent information about defect configurations across the phase transition despite the difference in the molecular alignment in the two phases.