Critical fluctuations and random-anisotropy glass transition in nematic elastomers

Abstract

We carry out a detailed deuterium nuclear magnetic resonance (NMR) study of local nematic ordering in polydomain nematic elastomers. This system has a close analogy to the random-anisotropy spin glass. We find that, in spite of the quadrupolar nematic symmetry in three dimensions requiring a first-order transition, the order parameter in the quenched ``nematic glass'' emerges via a continuous phase transition. In addition to this remarkable effect, by a careful analysis of the NMR line shape, we deduce that the local director fluctuations grow in a critical manner around the transition point. This could become an essential experimental evidence for the quenched disorder changing the order of discontinuous transition.