近日，日本东京大学Hirschberger, Max团队研究了一种具有相应自旋螺旋的金属p波磁铁。2025年10月22日出版的《自然》杂志发表了这项成果。

具有自旋分裂电子结构的反铁磁态，尽管（接近）零净磁化，仍会产生自旋电子、磁子和电子现象。最简单的奇宇称自旋分裂——p波——最初是由相互作用的电子系统中的集体不稳定性产生的。最近的理论已经确定了一种独特的途径来实现p波自旋分裂电子带，没有强相关性，称为p波磁性。

研究组演示了金属p波磁体的实验实现。非定域传导电子的奇偶价自旋分裂是由它们耦合到定域磁矩的反铁磁结构引起的：x射线散射实验表明，共面自旋螺旋的磁周期是化学单元胞的偶倍。这种结构打破了空间反演对称性，但在半单位胞平移范围内大致保持了时间反演对称性，从而满足了纵波磁性的对称性条件。与理论预测一致，它们的p波磁体在电子电导率方面表现出特征的各向异性。

相对论性自旋-轨道耦合和微小的自发净磁化进一步打破了时间反转对称性，导致巨大的异常霍尔效应（霍尔电导率>600 S cm^-1，霍尔角>3%)，用于反铁磁体。该模型计算表明，在p波磁体的电子结构中发现的自旋节点面很容易被一个小的扰动打断，从而诱发异常霍尔效应。研究组建立了金属p波磁体作为一个理想的平台来探索自旋分裂电子态在磁体、超导体和自旋电子器件中的功能。

附：英文原文

Title: A metallic p-wave magnet with commensurate spin helix

Author: Yamada, Rinsuke, Birch, Max T., Baral, Priya R., Okumura, Shun, Nakano, Ryota, Gao, Shang, Ezawa, Motohiko, Nomoto, Takuya, Masell, Jan, Ishihara, Yuki, Kolincio, Kamil K., Belopolski, Ilya, Sagayama, Hajime, Nakao, Hironori, Ohishi, Kazuki, Ohhara, Takashi, Kiyanagi, Ryoji, Nakajima, Taro, Tokura, Yoshinori, Arima, Taka-hisa, Motome, Yukitoshi, Hirschmann, Moritz M., Hirschberger, Max

Issue&Volume: 2025-10-22

Abstract: Antiferromagnetic states with a spin-split electronic structure give rise to spintronic, magnonic and electronic phenomena despite (near-)zero net magnetization1,2,3,4,5,6,7. The simplest odd-parity spin splitting—p wave—was originally proposed to emerge from a collective instability in interacting electron systems8,9,10,11,12. Recent theory has identified a distinct route to realize p-wave spin-split electronic bands without strong correlations13,14, termed p-wave magnetism. Here we demonstrate an experimental realization of a metallic p-wave magnet. The odd-parity spin splitting of delocalized conduction electrons arises from their coupling to an antiferromagnetic texture of localized magnetic moments: a coplanar spin helix whose magnetic period is an even multiple of the chemical unit cell, as revealed by X-ray scattering experiments. This texture breaks space-inversion symmetry but approximately preserves time-reversal symmetry up to a half-unit-cell translation—thereby fulfilling the symmetry conditions for p-wave magnetism. Consistent with theoretical predictions, our p-wave magnet shows a characteristic anisotropy in the electronic conductivity13,14,15. Relativistic spin–orbit coupling and a tiny spontaneous net magnetization further break time-reversal symmetry, resulting in a giant anomalous Hall effect (Hall conductivity >600Scm1, Hall angle >3%), for an antiferromagnet. Our model calculations show that the spin-nodal planes found in the electronic structure of p-wave magnets are readily gapped by a small perturbation to induce the anomalous Hall effect. We establish metallic p-wave magnets as an ideal platform to explore the functionality of spin-split electronic states in magnets, superconductors, and in spintronic devices.

DOI: 10.1038/s41586-025-09633-4

Source: https://www.nature.com/articles/s41586-025-09633-4