Magnetism in solids has been extensively studied in the field of condensed matter physics. A well-known example is ferromagnetism, which means that magnetic moments in a solid are spontaneously aligned to be parallel to each other owing to exchange interactions. Besides the ferromagnetism, there are various types of orders of magnetic moments, such as collinear antiferromagnetic and helical magnetic orders. Among them, non-collinear or non-coplanar magnetic orders have recently attracted increasing attention because they can lead to time-space symmetry breaking which may dramatically alter electronic properties of the systems. We study emergent phenomena induced by the non-collinear/non-coplanar spin orders by means of neutron and X-ray scattering techniques. One example is spin-driven ferroelectricity, where a spiral magnetic order breaks spatial inversion symmetry of the system and leads to spontaneous electric polarization. Another example is a vortex-like spin texture called magnetic skyrmiom, which often appears in a long-wavelength helimagnet. By the virtue of the topologically-nontrivial spin texture, the magnetic skyrmion induces an effective magnetic field acting only on conduction electrons. We are also exploring new methodologies in neutron and X-ray scatterings, such as time-resolved neutron scattering, to investigate the unconventional magnetic orders in detail.

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