Eur. Phys. J. E (2014) 37: 11
https://doi.org/10.1140/epje/i2014-14011-8

Regular Article

Low symmetry tetrahedral nematic liquid crystal phases: Ambidextrous chirality and ambidextrous helicity

¹ Max-Planck-Institute for Polymer Research, POBox 3148, 55021, Mainz, Germany
² Theoretische Physik III, Universität Bayreuth, 95440, Bayreuth, Germany

^* e-mail: pleiner@mpip-mainz.mpg.de
^** e-mail: brand@uni-bayreuth.de

Received: 2 January 2014
Revised: 14 February 2014
Accepted: 14 February 2014
Published online: 25 February 2014

Abstract

We discuss the symmetry properties as well as the dynamic behavior of various non-polar nematic liquid crystal phases with tetrahedral order. We concentrate on systems that show biaxial nematic order coexisting with octupolar (tetrahedral) order. Non-polar examples are phases with D₂ and S₄ symmetries, which can be characterized as biaxial nematics lacking inversion symmetry. It is this combination that allows for new features in the statics and dynamics of these phases. The D₂-symmetric phase is chiral, even for achiral molecules, and shows ambidextrous chirality in all three preferred directions. The achiral S₄-symmetric phase allows for ambidextrous helicity, similar to the higher-symmetric D_2d-symmetric phase. Such phases are candidates for nematic phases made from banana-shaped molecules.