Picture of scraped petri dish

Scrape below the surface of Strathprints...

The Strathprints institutional repository is a digital archive of University of Strathclyde research outputs. Explore world class Open Access research by researchers at Strathclyde, a leading technological university.

Explore

Tetrahedratic mesophases, chiral order, and helical domains induced by quadrupolar and octupolar interactions

Trojanowski, Karol and Pajak, Grzegorz and Longa, L. and Wydro, Thomas (2012) Tetrahedratic mesophases, chiral order, and helical domains induced by quadrupolar and octupolar interactions. Physical Review E, 86 (1). ISSN 1539-3755

[img] PDF
PhysRevE_86_011704.pdf - Published Version

Download (1MB)

Abstract

We present an exhaustive account of phases and phase transitions that can be stabilized in the recently introduced generalized Lebwohl-Lasher model with quadrupolar and octupolar microscopic interactions [ L. Longa, G. Pająk and T. Wydro Phys. Rev. E 79 040701 (2009)]. A complete mean-field analysis of the model, along with Monte Carlo simulations allows us to identify four distinct classes of the phase diagrams with a number of multicritical points where, in addition to the standard uniaxial and biaxial nematic phases, the other nematic like phases are stabilized. These involve, among the others, tetrahedratic (T), nematic tetrahedratic (NT), and chiral nematic tetrahedratic (NT*) phases of global Td, D2d, and D2 symmetry, respectively. Molecular order parameters and correlation functions in these phases are determined. We conclude with generalizations of the model that give a simple molecular interpretation of macroscopic regions with opposite optical activity (ambidextrous chirality), observed, e.g., in bent-core systems. An estimate of the helical pitch in the NT* phase is also given.