Magnetic-Field-Induced Polar Phase in Chiral Magnet CsCuCl$_3$

TL;DR

This study reveals a novel polar solitonic multiferroic phase in the chiral magnet CsCuCl₃ induced by magnetic fields, characterized by magnetization plateaus and electric polarization.

Contribution

It demonstrates the emergence of a magnetic-field-induced polar phase in CsCuCl₃, combining experimental magnetization and polarization measurements with symmetry analysis.

Findings

Electric polarization appears between magnetization plateau and jump.

The phase is explained as a polar solitonic state due to chiral spin arrangements.

Paramagnetoelectric effect is confirmed in the material.

Abstract

Magnetoelectric effects in the chiral magnet CsCuCl$_3$ have been investigated through the 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 0.25 {\mu}C/m$^2$ 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 the 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 novel multiferroic phase in CsCuCl$_3$ as a polar solitonic phase.