Fig. 1.

Topological analogy: electric versus magnetic states. (A) Uniform magnetization or polarization. (B) Helimagnet or helielectric states. Possible helicoidal (top) and heliconical (bottom) textures are shown. (C) Molecular structure of the polar anisotropic entity, RM734. The molecular polar dipole is nearly parallel to the long molecular axis. (D) The ferroelectric nematic state with spontaneous polarization. (E) HN* state with heli realized by adding chiral generators into the polar chiral nematic state. One-dimensional polarization fields are also depicted in D and E for clarity. (F) The molecular structures of the chiral generators S1 and S2. (G) The state diagram of the two HN* materials by mixing RM734 with S1 or S2.