Chiral Symmetry Breaking in Bent-Core Liquid Crystals

TL;DR

This paper uses molecular modeling to identify new spatially homogeneous phases, including a chiral tetrahedratic nematic phase, in bent-core liquid crystals, revealing spontaneous chiral symmetry breaking in non-layered systems.

Contribution

It introduces the first molecular model demonstrating spontaneous chiral symmetry breaking in non-layered bent-core liquid crystals.

Findings

Identification of tetrahedratic ($T$), $N_T$, and $N_T^*$ phases.

Discovery of a chiral tetrahedratic nematic ($N_T^*$) phase.

Phase diagrams showing multiple liquid crystal phases.

Abstract

By molecular modeling we demonstrate that the nematic long-range order discovered in bent-core liquid crystal systems should reveal further spatially homogeneous phases. Two of them are identified as a tetrahedratic nematic ($N_T$) phase with $D_{2d}$ symmetry and a chiral tetrahedratic nematic ($N_T^*$) phase with $D_2$ symmetry. These new phases were found for a lattice model with quadrupolar and octupolar anisotropic interactions using Mean Field theory and Monte Carlo simulations. The phase diagrams exhibit tetrahedratic ($T$), $N_T$ and $N_T^*$ phases, in addition to ordinary isotropic ($I$), uniaxial nematic ($N_U$) and biaxial nematic ($N_B$) phases. To our knowledge, this is the first molecular model with spontaneous chiral symmetry breaking in non-layered systems.