Magnetic field induced polar phase in the chiral magnet CsCuCl3

Magnetoelectric effects in the chiral magnet CsCuCl3 have been investigated through magnetization and electric polarization measurements in pulsed high magnetic fields. If the magnetic field is applied normal to the spin chiral c axis, a plateau and a jump in magnetization are observed. Between the plateau and the jump in magnetization, a small but significant electric polarization of about 0.25μC/m2 along the a axis is observed with the field applied almost perpendicular to the ac plane. In addition, the paramagnetoelectric effect expected from the point group symmetry is confirmed. The emergence of electric polarization is explained by the cooperation of the local electric polarization on the chiral solitonic spin arrangement and the paramagnetoelectric effect. Hence, we interpret this multiferroic phase in CsCuCl3 as a polar solitonic phase.