Amount Of Chiral Research Articles

Morphological, optical and dielectric behavior of chiral nematic liquid crystal mixture: Study on effect of different amount of chirality

We report the effect of chiral concentration on temperature dependent helical pitch of a chiral nematic liquid crystal system. The phase behaviour, optical and dielectric properties of binary mixtures of a nematic liquid crystal 4-pentyl-4′-cyano-biphenyl and a chiral liquid crystal cholesteryl oleyl carbonate in five different ratios was investigated. The study shows that by introducing optimum chirality into the molecule of nematogen leads to improved thermochromism performance and creation of new mesophases. The blue phase appeared in mixtures in large temperature window, including room temperatures. Many fold enhancement in the photoluminescence intensity was observed with an increase in chiral concentration. We have noticed considerable periodic alternation of temperature dependent refractive index in the visible spectral region, which is resulted by small pitch and more prominent chirality especially in the mixture of 30% nematic and 70% chiral composition. The dielectric loss decreased in mixtures particularly in lower frequency region.

Charged excitations of the chiral spin liquid.

We propose specific wave functions for the charged, spinless excitations hypothesized to exist in chiral spin liquids and show, in the context of the t-J Hamiltonian, that their variational energy and mobility are superior to those of ordinary holes. We find that these quantities limit to finite values as the amount of chirality in the ground state diminishes to zero, but that the statistics become abruptly ill defined in this limit.