8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

P3.32Fri 911:10-14:00Continuum theory for smectic A liquid crystalsIain Stewart 11 University of Strathclyde, Department of Mathematics and Statistics, 26 Richmond StreetG1 1XH, Glasgow, United KingdomNematic liquid crystals consist of rod-like molecules that have a preferred average directiondescribed by a unit vector n. Many nematics, when cooled, exhibit a structure of moleculesarranged in parallel layers to form smectic A (SmA) liquid crystals, modelled by n or the localsmectic layer normal a. In previous models [1, 2], a and n coincide, but this is not generally valid[3]. The model discussed here [4] allows their separation. Distortions to the smectic layers arisebecause of boundary conditions or externally applied magnetic or electric fields. Comparisonswith the classical theories [1, 2] and the recent theory [4] will be made. The boundary layer phenomenareported by Elston [5] for SmA can be described remarkably well [6] by this recent theory.[1] P G de Gennes and J Prost, The Physics of Liquid Crystals. OUP, 1993.[2] I W Stewart, The Static and Dynamic Continuum Theory of Liquid Crystals. Taylor andFrancis, London and New York, 2004.[3] G K Auernhammer, H R Brand and H Pleiner, Phys. Rev. E, 66, 061707 (2002).[4] I W Stewart, Continuum Mech. Thermodyn. , 18, 343-360 (2007).[5] S J Elston, Liq. Cryst. , 16, 151-157 (1994).[6] R De Vita and I W Stewart, J. Phys. : Condens. Matter, 20, 335101 (2008).32