title: Helical nanofilament phases.
abstract: In the formation of chiral crystals, the tendency for twist in the orientation of neighboring molecules is incompatible with ordering into a lattice: Twist is expelled from planar layers at the expense of local strain. We report the ordered state of a neat material in which a local chiral structure is expressed as twisted layers, a state made possible by spatial limitation of layering to a periodic array of nanoscale filaments. Although made of achiral molecules, the layers in these filaments are twisted and rigorously homochiral--a broken symmetry. The precise structural definition achieved in filament self-assembly enables collective organization into arrays in which an additional broken symmetry--the appearance of macroscopic coherence of the filament twist--produces a liquid crystal phase of helically precessing layers.
authors.affiliation: Department of Physics and Liquid Crystal Materials Research Center, University of Colorado, Boulder, CO 80309, USA. hough@colorado.edu
authors.forename: L E
authors.initials: LE
authors.lastname: Hough
authors.forename: H T
authors.initials: HT
authors.lastname: Jung
authors.forename: D
authors.initials: D
authors.lastname: Krüerke
authors.forename: M S
authors.initials: MS
authors.lastname: Heberling
authors.forename: M
authors.initials: M
authors.lastname: Nakata
authors.forename: C D
authors.initials: CD
authors.lastname: Jones
authors.forename: D
authors.initials: D
authors.lastname: Chen
authors.forename: D R
authors.initials: DR
authors.lastname: Link
authors.forename: J
authors.initials: J
authors.lastname: Zasadzinski
authors.forename: G
authors.initials: G
authors.lastname: Heppke
authors.forename: J P
authors.initials: JP
authors.lastname: Rabe
authors.forename: W
authors.initials: W
authors.lastname: Stocker
authors.forename: E
authors.initials: E
authors.lastname: Körblova
authors.forename: D M
authors.initials: DM
authors.lastname: Walba
authors.forename: M A
authors.initials: MA
authors.lastname: Glaser
authors.forename: N A
authors.initials: NA
authors.lastname: Clark
mesh_terms: D003460:Crystallization; D018625:Microscopy, Atomic Force; D046529:Microscopy, Electron, Transmission; D008859:Microscopy, Polarization; D015394:Molecular Structure; D049329:Nanostructures; D014961:X-Ray Diffraction