  We describe a soft matter system of self-organized oblate micelles and
plasmonic gold nanorods that exhibit a negative orientational order parameter.
Because of anisotropic surface anchoring interactions, colloidal gold nanorods
tend to align perpendicular to the director describing the average orientation
of normals to the discoidal micelles. Helicoidal structures of highly
concentrated nanorods with a negative order parameter are realized by adding a
chiral additive and are further controlled by means of confinement and
mechanical stress. Polarization-sensitive absorption, scattering, and
two-photon luminescence are used to characterize orientations and spatial
distributions of nanorods. Self-alignment and effective-medium optical
properties of these hybrid inorganic-organic complex fluids match predictions
of a simple model based on anisotropic surface anchoring interactions of
nanorods with the structured host medium.
