A magnon is a collective excitation of the spin structure in a magnetic insulator and can transmit spin angular momentum with negligible dissipation. This quantum of a spin wave has always been manipulated through magnetic dipoles (that is, by breaking time-reversal symmetry). Here we report the experimental observation of chiral spin transport in multiferroic BiFeO₃ and its control by reversing the ferroelectric polarization (that is, by breaking spatial inversion symmetry). The ferroelectrically controlled magnons show up to 18% modulation at room temperature. The spin torque that the magnons in BiFeO₃ carry can be used to efficiently switch the magnetization of adjacent magnets, with a spin–torque efficiency comparable to the spin Hall effect in heavy metals. Utilizing such controllable magnon generation and transmission in BiFeO₃, an all-oxide, energy-scalable logic is demonstrated composed of spin–orbit injection, detection and magnetoelectric control. Our observations open a new chapter of multiferroic magnons and pave another path towards low-dissipation nanoelectronics.

磁振子是磁绝缘体中自旋结构的集体激发，可以以可忽略不计的耗散传递自旋角动量。自旋波的这个量子一直是通过磁偶极子（即，通过打破时间反转对称性）来操纵的。在这里，我们报告了多铁性 BiFeO ₃中手性自旋输运的实验观察及其通过反转铁电极化（即通过打破空间反演对称性）进行控制。铁电控制磁振子在室温下表现出高达 18% 的调制。 BiFeO ₃中的磁振子携带的自旋扭矩可用于有效地切换相邻磁体的磁化强度，其自旋扭矩效率与重金属中的自旋霍尔效应相当。利用BiFeO ₃中这种可控磁振子的产生和传输，展示了一种由自旋轨道注入、检测和磁电控制组成的全氧化物能量可扩展逻辑。我们的观察开启了多铁磁振子的新篇章，并为低耗散纳米电子学铺平了另一条道路。