Dephasing of transverse spin current in ferrimagnetic alloys
Dephasing of transverse spin current in ferrimagnetic alloys
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DOI：
10.1103/physrevb.103.024443
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发表时间：
2021-01-26
影响因子：
3.7
通讯作者：
Emori, Satoru
中科院分区：
文献类型：
--
作者：
Lim, Youngmin;Khodadadi, Behrouz;Emori, Satoru
据预测，横向自旋电流可以在反铁磁有序金属中进行长距离的相干（无消相）传播。在这里，我们通过测量补偿点上的自旋泵来估计铁磁CoGd合金中横向自旋电流的消相长度。一个修正的漂移-扩散模型，解释了自旋电流通过铁磁体的传输，揭示了近补偿的CoGd的减相长度比铁磁金属长4-5倍。这一发现表明，即使在室温下结构无序的合金中，反铁磁有序也可以减轻自旋失相——以一种类似于原子核和量子比特自旋系统的自旋回波重相的方式。我们还发现横向自旋电流与Co亚晶格的相互作用比与Gd亚晶格的相互作用更强。我们的研究结果为自旋电流和反铁磁有序之间的相互作用提供了基本的见解，这对于铁磁和反铁磁金属的工程自旋扭矩效应至关重要。
It has been predicted that transverse spin current can propagate coherently (without dephasing) over a long distance in antiferromagnetically ordered metals. Here, we estimate the dephasing length of transverse spin current in ferrimagnetic CoGd alloys by spin pumping measurements across the compensation point. A modified drift-diffusion model, which accounts for spin-current transmission through the ferrimagnet, reveals that the dephasing length is about 4-5 times longer in nearly compensated CoGd than in ferromagnetic metals. This finding suggests that antiferromagnetic order can mitigate spin dephasing-in a manner analogous to spin echo rephasing for nuclear and qubit spin systems-even in structurally disordered alloys at room temperature. We also find evidence that transverse spin current interacts more strongly with the Co sublattice than the Gd sublattice. Our results provide fundamental insights into the interplay between spin current and antiferromagnetic order, which are crucial for engineering spin torque effects in ferrimagnetic and antiferromagnetic metals.