Anisotropic Magnon-Magnon Coupling in Synthetic Antiferromagnets
Anisotropic Magnon-Magnon Coupling in Synthetic Antiferromagnets
复制标题
合成反铁磁体中的各向异性磁振子-磁振子耦合
DOI：
10.1088/0256-307x/38/5/057502
复制
发表时间：
2021-06-01
影响因子：
3.5
通讯作者：
Lu, Jie
中科院分区：
文献类型：
--
作者：
He, Wei;Xie, Z. K.;Lu, Jie
人工合成反铁磁体中的磁振子-磁振子耦合使得它可以作为混合磁振子系统来探索量子信息技术。为了诱导磁振子-磁振子耦合，需要打破两个磁化之间的宇称对称性。在这里，我们实验证明了一个方便的方法来打破宇称对称性的不对称结构。我们成功地在合成的Ir基反铁磁体CoFeB（10 nm）/Ir（t（Ir）= 0.6 nm，1.2 nm）/CoFeB（13 nm）中引入了磁振子-磁振子耦合。值得注意的是，我们发现，弱单轴各向异性场（类似于20 Oe）使磁振子-磁振子耦合各向异性。当t（Ir）= 0.6 nm时，由特征反交叉带隙表示的耦合强度在0.54 GHz和0.90 GHz之间变化，当t（Ir）= 1.2 nm时，在0.09 GHz和1.4 GHz之间变化。我们的研究结果表明，通过非对称结构诱导磁振子-磁振子耦合，并通过改变面内磁场的方向来调节耦合强度是可行的。在这种高度可调谐的材料系统中的磁振子-磁振子耦合可以为探索量子力学耦合现象打开令人兴奋的前景。
Magnon-magnon coupling in synthetic antiferromagnets advances it as hybrid magnonic systems to explore the quantum information technologies. To induce magnon-magnon coupling, the parity symmetry between two magnetization needs to be broken. Here we experimentally demonstrate a convenient method to break the parity symmetry by the asymmetric structure. We successfully introduce a magnon-magnon coupling in Ir-based synthetic antiferromagnets CoFeB(10 nm)/Ir(t (Ir) = 0.6 nm, 1.2 nm)/CoFeB(13 nm). Remarkably, we find that the weakly uniaxial anisotropy field (similar to 20 Oe) makes the magnon-magnon coupling anisotropic. The coupling strength presented by a characteristic anticrossing gap varies in the range between 0.54 GHz and 0.90 GHz for t (Ir) = 0.6 nm, and between 0.09 GHz and 1.4 GHz for t (Ir) = 1.2 nm. Our results demonstrate a feasible way to induce magnon-magnon coupling by an asymmetric structure and tune the coupling strength by varying the direction of in-plane magnetic field. The magnon-magnon coupling in this highly tunable material system could open exciting perspectives for exploring quantum-mechanical coupling phenomena.