Evidence for a topological transition in nematic-to-isotropic phase transition in two dimensions

The nematic-to-isotropic orientational phase transition, or equivalently the RP2 model, is considered in two dimensions and the question of the nature of the phase transition is addressed. Using powerful conformal techniques adapted to the investigation of critical properties of two-dimensional scale-invariant systems, we report strong evidences for a transition governed by topological defects analogous to the Berezinskii-Kosterlitz-Thouless transition in two-dimensional XY model