title: Direct measurement of the twist penetration length in a single smectic A layer of colloidal virus particles.
abstract: In the 1970s, deGennes discussed the fundamental geometry of smectic liquid crystals and established an analogy between the smectic A phase and superconductors. It follows that smectic layers expel twist deformations in the same way that superconductors expel magnetic field. We make a direct observation of the penetration of twist at the edge of a single isolated smectic A layer composed of chiral fd virus particles subjected to a depletion interaction. Using the LC-PolScope, we make quantitative measurements of the spatial dependence of the birefringence due to molecular tilt near the layer edges. We match data to theory for the molecular tilt penetration profile and determine the twist penetration length for this system.
authors.affiliation: The Martin Fisher School of Physics, Brandeis University, Waltham, Massachusetts 02454, USA.
authors.forename: Edward
authors.initials: E
authors.lastname: Barry
authors.forename: Zvonimir
authors.initials: Z
authors.lastname: Dogic
authors.forename: Robert B
authors.initials: RB
authors.lastname: Meyer
authors.forename: Robert A
authors.initials: RA
authors.lastname: Pelcovits
authors.forename: Rudolf
authors.initials: R
authors.lastname: Oldenbourg
mesh_terms: D003102:Colloids / Q000737:chemistry; D050866:Liquid Crystals / Q000737:chemistry; D008956:Models, Chemical; D010316:Particle Size; D013499:Surface Properties; D014771:Virion / Q000737:chemistry; D014780:Viruses / Q000737:chemistry*
chemical_list: D003102:Colloids