Chirality or the handedness of objects is of prime importance in life science, biology, chemistry, and physics. It is also a major symmetry ingredient in frustrated magnets revealing spin-spiral ground states. Vector-chiral phases, with the twist (either clock- or counter clock-wise) between neighboring spins being ordered, but with disorder with respect to the angles between adjacent spins, have been predicted almost five decades ago. Experimental proofs, however, are rare and controversial. Here, we provide experimental evidence for such a phase in LiCuVO₄, a one-dimensional quantum magnet with competing ferromagnetic and antiferromagnetic interactions. The vector-chiral state is identified via a finite ferroelectric polarization arising at temperatures well above the multiferroic phase exhibiting long-range three-dimensional spin-spiral and polar order. On increasing temperatures, spin order becomes suppressed at T_N, whereas chiral long-range order still exist, leaving a temperature window with chirality-driven ferroelectricity in the presence of an external magnetic field.

对象的手性或手性在生命科学，生物学，化学和物理学中至关重要。它也是受挫磁体中显示自旋-螺旋基态的主要对称成分。大约在50年前就已经预测到矢量手性相位，其中相邻旋转之间的扭曲是有序的（顺时针或逆时针），但是相邻旋转之间的角度是无序的。但是，实验证明很少见且有争议。在这里，我们为LiCuVO _4中的这一相提供了实验证据。，是具有竞争铁磁和反铁磁相互作用的一维量子磁体。通过在远高于多铁性相的温度下出现的有限铁电极化来确定矢量手性状态，该铁性相表现出长程三维自旋螺旋和极性顺序。随着温度的升高，自旋序在T _N处受到抑制，而手性远程序仍然存在，从而在存在外部磁场的情况下留下具有手性驱动的铁电的温度窗口。