Topology and Nematic Ordering II: Observable Critical Behavior

TL;DR

This paper investigates the observable critical behaviors and experimental signatures of a new topologically ordered phase in a lattice model for nematic media, focusing on phase transitions and critical phenomena.

Contribution

It provides the first detailed analysis of experimental signatures and critical behavior near the topologically ordered phase in nematic systems, complementing previous theoretical work.

Findings

Critical behavior of specific heat, light scattering, and magnetic susceptibility near phase transitions.

Singular temperature dependence of Frank constants and dielectric anisotropy near N/T transition.

Identification of experimental signatures for the topologically ordered phase.

Abstract

This paper is the second in a pair treating a new lattice model for nematic media. In addition to the familiar isotropic (I) and nematically ordered (N) phases, the phase diagram established in the previous paper (Paper I) contains a new, topologically ordered phase (T) occuring at large suppression of topological defects and weak nematic interactions. This paper (Paper II) is concerned with the experimental signatures of the proposed phase diagram. Specific heat, light scattering and magnetic susceptibility near both the N/T and I/T transitions are studied, and critical behavior determined. The singular dependences of the Frank constants ($K_1$, $K_2$, $K_3$) and the dielectric tensor anisotropy ($\Delta \epsilon$) on temperature upon approaching the N/T transition are also found.