History-dependent patterns in randomly perturbed nematic liquid crystals

Amid Ranjkesh Siahkal (Author), Milan Ambrožič (Author), George Cordoyiannis (Author), Zdravko Kutnjak (Author), Samo Kralj (Author)

Abstract

We study the characteristics of nematic structures in a randomly perturbed nematic liquid crystal (LC) phase. We focus on the impact of the samples history on the universal behavior. The obtained results are of interest for every randomly perturbed system exhibiting a continuous symmetry-breaking phase transition. A semimicroscopic lattice simulation is used where the LC molecules are treated as cylindrically symmetric, rod-like objects interacting via a Lebwohl-Lasher (LL) interaction. Pure LC systems exhibit a first order phase transition into the orientationally ordered nematic phase at T = Tc on lowering the temperature T. The orientational ordering of LC molecules is perturbed by the quenched, randomly distributed rod-like impurities of concentration p. Their orientation is randomly distributed, and they are coupled with the LC molecules via an LL-type interaction. Only concentrations below the percolation threshold are considered. The key macroscopic characteristics of perturbed LC structures in the symmetry-broken nematic phase are analyzed for two qualitatively different histories at T << Tc. We demonstrate that, for a weak enough interaction among the LC molecules and impurities, qualitatively different history-dependent states could be obtained. These states could exhibit either short-range, quasi-long-range, or even long-range order.

Keywords

liquid crystals;

Data

Language:	English
Year of publishing:	2013
Typology:	1.01 - Original Scientific Article
Organization:	UM FNM - Faculty of Natural Sciences and Mathematics
UDC:	53
COBISS:	26806567
ISSN:	1687-8108
Views:	1132
Downloads:	287
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	tekoči kristali;
URN:	URN:SI:UM:
Type (COBISS):	Scientific work
Pages:	str. 505219-1-505219-10
Volume:	ǂVol. ǂ2013
Chronology:	2013
DOI:	10.1155/2013/505219
ID:	10842662