One of the research goals in our group is to find a novel quantum phenomenon and to reveal its mechanism in low-dimensional spin magnets and frustrated magnets. Strong quantum fluctuation or geometrical frustration disturbs the development of trivial magnetic states and induces a non-trivial quantum state. Furthermore, such a state is sensitive to a small perturbation and, thus, the area is frontier of quantum phenomena. Our research topic includes spin liquid, RVB, Cuboc structure, etc. Another goal is to observe a new magnetoelectric effect in multiferroic compounds and/or relaxor magnets. Figure shows inelastic neutron scattering spectrum measured on multiferroics Ba₂MnGe₂O₇. Energy gap at k = 0 of acoustic magnon (T₁) mode originates from spin nematic interaction, and its temperature dependence is scaled by electric polarization instead of magnetic moment. The nontrivial behavior of the anisotropy gap can be rationalized as change of the hybridized d-p orbital with temperature.

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