Pressure-induced twist grain boundary phase

Abstract

Extension of de Gennes' analogy of the nematic-smectic A transition to chiral systems has led to the prediction of a new phase, referred to as the Twist Grain Boundary (TGB) phase. Experiments on this phase has attracted a wide attention since it is the liquid crystal analogue of the Abrikosov flux lattice phase in Type 11 superconductors. In support of the theoretical predic- tion, we had identified the existence of this phase in the vicinity of a virtual cholesteric-smectic A-smectic C* meeting point. Based on our earlier experience regarding pressure induced mesormorphism we expected to observe an induced TGB phase in a suitable material. Our very recent experiments have indeed proved this expectation to be true.