Possible chiral magnetism in CuB₂ O₄

We reported here commensurate-to-incommensurate (C-IC) magnetic ordering in copper metaborate CuB₂ O₄ on the basis of concomitant chiral soliton lattice formation. We measured the magnetization processes in detail under the applied magnetic fields parallel and perpendicular to the helical axis. We found the anomalous temperature and magnetic field dependence of the magnetization strongly anisotropic with respect to the applied magnetic fields. The experimental results were quite consistent with the theoretical prediction based on the lattice chiral XY model, which describes the C-IC transition as the chiral soliton picture.