Possible experiments on two-dimensional nematics

Abstract

It may be possible to obtain liquid monolayers at a water/air interface, with long and rigid bifunctional molecules, which would be attached by both ends to the water surface. At sufficient compressions, the molecules might become locally aligned parallel to each other. However, (in the absence of external fields) long-range nematic order would not be allowed, because of the large fluctuations in orientation which are characteristic of a two-dimensional phase with continuous rotational degeneracy. We discuss here the light scattering due to these fluctuations, and conclude that this scattering may be observable, if spurious signals due to surface waves are eliminated by a suitable choice of polarizations.