Ma Meiyang, Wu Jing, Liu Bo, Wang Lei, Li Zhuoyi, Ruan Xuezhong, Hu Zehua, Wang Fengqiu, Lu Xianyang, Liu Tianyu, Du Jun, Xia Ke, Xu Yongbing
National Key Laboratory of Spintronics, Nanjing University, Suzhou, China.
School of Electronic Science and Engineering, Nanjing University, Nanjing, China.
Nat Commun. 2025 May 12;16(1):4401. doi: 10.1038/s41467-025-59689-z.
Synthetic antiferromagnetics (SAF) provide an excellent platform for antiferromagnetic spintronics. Recently, the voltage-control of the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in SAFs was studied experimentally. Optical control would offer unique opportunities for the ultrafast manipulation of spin states, however, it has yet to be demonstrated. Here, using femtosecond laser excitations in a [Co/Pt]-based perpendicular magnetic anisotropy (PMA) synthetic antiferromagnet (p-SAF), we drive a reduction of the RKKY coupling and the PMA. We attribute the reduced RKKY interaction to the optically smeared Fermi wave vector of the Ru layer, which mediates the exchange coupling between the constituent ferromagnetic layers. The PMA exhibits the same amplitude of decrease as the RKKY coupling, which we associate with electron redistributions in the 3d orbitals caused by the optically smeared Fermi level. While the pump excitation process is shown to have an influence on the modulations, thermal contributions are excluded. Our study establishes a link between the RKKY coupling and the PMA in a p-SAF structure and provides an approach to tune them in parallel.
合成反铁磁体（SAF）为反铁磁自旋电子学提供了一个出色的平台。最近，人们通过实验研究了SAF中Ruderman-Kittel-Kasuya-Yosida（RKKY）相互作用的电压控制。光学控制将为自旋态的超快操纵提供独特的机会，然而，这一点尚未得到证实。在此，我们利用基于[Co/Pt]的垂直磁各向异性（PMA）合成反铁磁体（p-SAF）中的飞秒激光激发，实现了RKKY耦合和PMA的降低。我们将RKKY相互作用的降低归因于Ru层光学展宽的费米波矢，它介导了组成铁磁层之间的交换耦合。PMA的降低幅度与RKKY耦合相同，我们将其与光学展宽的费米能级引起的3d轨道中的电子重新分布联系起来。虽然泵浦激发过程显示出对调制有影响，但排除了热贡献。我们的研究建立了p-SAF结构中RKKY耦合与PMA之间的联系，并提供了一种并行调节它们的方法。
