Nematics with Quenched Disorder: How Long Will It Take to Heal?

Abstract

Nematics with quenched disorder have been repeatedly predicted to form glass phases. Here we present turbidity experiments and computer simulations aimed at studying glass key features such as dynamics and history dependence in randomly perturbed nematics. Electric field-cooling alignment has been employed to prepare samples in suitably oriented starting states. Remarkable remnant order and slow dynamics are found both by experiment and simulations, indicating that random disorder can, by itself, induce a nematic glass state even without perturber restructuring.

Molecular dynamics of a short-range ordered smectic phase nanoconfined in porous silicon

“…4 Although it seems a quite general behavior, the connection between the glass-like 4 dynamics of confined LC's and the nature of the porous topology, surface interactions and confinement-induced quenched disorder effects remains challenging. 21,22,23,24 The individual molecular dynamics of confined LC's is also strongly modified. Dielectric relaxation spectroscopy has been extensively used since it allows one to probe the rotationallibrational dynamics of the dipolar molecules around their short axis as well as tumbling relaxation modes around the local nematic director.…”

Evolution of the isotropic-to-nematic phase transition in octyloxycyanobiphenyl+aerosil dispersions

“…x-ray scattering [14,15], x-ray intensity fluctuation spectroscopy [16], static and dynamic light-scattering [9,10,11], and deuterium NMR [17] studies on the nematic to smectic-A (N -SmA) and the isotropic to nematic (I -N ) phase transitions of this system have shown that there are clear quenched random-field characteristics as well as finite-size scaling effects…”

Nematics with Quenched Disorder: Pinning out the Origin of Memory

“…In the simulations we mimic the FC and ZFC states by studying the evolution from an Aligned (AIC 0 , with all aligned spins) and a Random Initial Configuration (RIC 0 ) [11]. The corresponding equilibrated configurations, here after referred to as AIC and RIC states, respectively, are remarkably different [11]. In Fig.…”

“…The value of P2 for these equilibrated states is generally overestimated because of finite-size effect and decreases with increasing lattice size [12] as shown in the inset of Fig.1. In the simulations we mimic the FC and ZFC states by studying the evolution from an Aligned (AIC 0 , with all aligned spins) and a Random Initial Configuration (RIC 0 ) [11]. The corresponding equilibrated configurations, here after referred to as AIC and RIC states, respectively, are remarkably different [11].…”