p波磁铁的电开关
近日，美国麻省理工学院Riccardo Comin团队研究了p波磁铁的电开关。该研究于2025年5月28日发表在《自然》杂志上。
具有零磁化但非相对论自旋分裂的磁态是下一代自旋电子器件的杰出候选者。它们的电子伏特（eV）级自旋分裂、超快自旋动力学和几乎消失的杂散场使其在多种应用中特别有前景。最近发现了各种具有非平凡自旋结构的磁态，包括偶奇偶d波、g波或i波交替磁体和奇奇偶p波磁体。
实现对这些磁态的非均匀自旋极化的基于电压的控制对于实现用于信息存储和处理的节能和紧凑的器件具有重要意义。自旋螺旋II型多铁性材料是这种基于电压的控制的最佳候选者，因为它们表现出直接诱导铁电极化的反转对称破磁序，允许自旋手性和极性序之间的对称保护交叉控制。
研究组结合了光电流测量、第一性原理计算和群论分析，提供了直接证据，证明自旋螺旋型II多铁性NiI2的自旋极化表现出与螺旋手性相关的奇偶性特征。手性和极序之间的对称保护耦合使得能够对主要的非相对论自旋极化进行电控制。该发现代表了对自旋螺旋II型多铁性中p波磁性的观察，这可能会导致补偿磁体中非相对论自旋极化的电压切换的发展。
附：英文原文
Title: Electrical switching of a p-wave magnet
Author: Song, Qian, Stavri, Srdjan, Barone, Paolo, Droghetti, Andrea, Antonenko, Daniil S., Venderbos, Jrn W. F., Occhialini, Connor A., Ilyas, Batyr, Ergeen, Emre, Gedik, Nuh, Cheong, Sang-Wook, Fernandes, Rafael M., Picozzi, Silvia, Comin, Riccardo
Issue&Volume: 2025-05-28
Abstract: Magnetic states with zero magnetization but non-relativistic spin splitting are outstanding candidates for the next generation of spintronic devices. Their electronvolt (eV)-scale spin splitting, ultrafast spin dynamics and nearly vanishing stray fields make them particularly promising for several applications1,2. A variety of such magnetic states with non-trivial spin textures have been identified recently, including even-parity d-wave, g-wave or i-wave altermagnets and odd-parity p-wave magnets3,4,5,6,7. Achieving voltage-based control of the non-uniform spin polarization of these magnetic states is of great interest for realizing energy-efficient and compact devices for information storage and processing8,9. Spin-spiral type II multiferroics are optimal candidates for such voltage-based control, as they exhibit an inversion-symmetry-breaking magnetic order that directly induces ferroelectric polarization, allowing for symmetry-protected cross-control between spin chirality and polar order10,11,12,13,14. Here we combine photocurrent measurements, first-principles calculations and group-theory analysis to provide direct evidence that the spin polarization of the spin-spiral type II multiferroic NiI2 exhibits odd-parity character connected to the spiral chirality. The symmetry-protected coupling between chirality and polar order enables electrical control of a primarily non-relativistic spin polarization. Our findings represent an observation of p-wave magnetism in a spin-spiral type II multiferroic, which may lead to the development of voltage-based switching of non-relativistic spin polarization in compensated magnets.
DOI: 10.1038/s41586-025-09034-7