Dr Roger Johnson - BiCuxMn7-xO12: Polar antiferromagnetism by inverse exchange-striction and an emergent helical texture of electric dipoles

His research group works on the experimental determination of structure-property relationships in quantum materials and their theoretical interpretation via phenomenological group and Landau theories. At present they are focused on magneto-orbital physics of novel quadruple perovskite manganites, model quantum magnets engineered from coordination polymers, the crystal and magnetic structures of candidate Kitaev systems, and multiferroic thin film devices for oxide electronics.

They perform laboratory-based experiments using, for example, a Quantum Design Magnetic Properties Measurement System and Physical Properties Measurement System, bespoke dielectric and ferroelectric instrumentation, and single crystal and powder x-ray diffractometers. Their core research involves experiments at large-scale central facilities, mostly the ISIS Neutron and Muon Source and Diamond Light Source.