Liquid crystals are well-known for their strong response to the external electric field. This response however is typically independent of the sign of external electric field. Suspensions of magnetic nanoplatelets in liquid crystal media on the other hand exhibit spontaneous magnetic ordering and thus respond linearly to the external magnetic field. Hence moderate magnetic fields can be used to control the structure of the material, which is in our case confined to a thin ordered layer. If the chosen liquid crystal media is chiral (cholesteric liquid crystals), the resulting material is even more interesting. Wound cholesteric ground state competes with homogeneous external aligning fields and boundary conditions on the layer borders. It turns out that many complex polar structures can be stabilised with the combination of external electric and magnetic fields. Additionally, the dynamic is in this case no longer invariant to the sign of electric field, when the external magnetic field is simultaneously applied. This is a consequence of the specific symmetry breakings due to the chirality of cholesteric liquid crystals and spontaneous magnetisation. Here, several features of this material are described and experiments examining the morphology and dynamics are presented.
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