Chiral helimagnetism in T1/3NbS2 (T=Cr and Mn)

We report commensurate-to-incommensurate (C–IC) magnetic ordering in T1/3NbS2 (T=Cr and Mn), of which space group is P6322. We measured the anisotropic magnetization under magnetic fields applied perpendicular and parallel to the hexagonal c-axis. We observed a magnetization anomaly, only when the magnetic field was applied perpendicular to the hexagonal c-axis. The experimental results were in good agreement with the theoretical prediction based on a lattice chiral XY model, which describes the C–IC transition as chiral soliton formation. Therefore, we propose that the magnetic ordering in an incommensurate phase of T1/3NbS2 (T=Cr and Mn) can be chiral helimagnetic.