Extended Data Fig. 8: Monoclinic and magnetic-field-induced triclinic smectic order.
From: Thermally reconfigurable monoclinic nematic colloidal fluids
a–d, Upconversion-based luminescence confocal microscopy images (a, b) and numerical visualizations (c, d) of disks in the monoclinic smectic phase at ρ ≈ 0.3 μm−3, T = 32.3 ± 0.1 °C and θne ≈ 45° (a, c) and for the magnetically induced triclinic smectic state under otherwise similar conditions (b, d). The smectic layer normal (yellow double arrow), nc and nm are initially within the image plane (a, c), but then nc is rotated out of the image plane by a magnetic field of B = 100 mT (b), thus switching the smectic order from monoclinic (a, c) to triclinic (b, d). This switching is driven by the tendency of ωc and nc to align perpendicular to B, where the disk normals also tend to reside on a cone of anchoring-defined easy-angle ωc orientations. Right-side insets of a, b show the layer normal, nm, nc and n⊥ and the applied magnetic field B for the monoclinic and the triclinic smectic states, respectively. The layer normal, nc and n⊥ are all mutually orthogonal and the layer normal, nc and nm are all co-planar in a but not in b, which lacks nontrivial symmetry operations and represents triclinic symmetry.
