Physics Department, Simon Fraser University, Burnaby, British Columbia, Canada.
Phys Rev Lett. 2011 Aug 5;107(6):066604. doi: 10.1103/PhysRevLett.107.066604. Epub 2011 Aug 2.
Spin injection across the ferrimagnetic insulator (YIG)/normal metal (Au) interface was studied by ferromagnetic resonance. The spin mixing conductance was determined by comparing the Gilbert damping in bare YIG films with those covered by a Au/Fe/Au structure. The Fe layer in Au/Fe/Au acted as a spin sink as displayed by an increased Gilbert damping parameter α compared to that in the bare YIG. In particular, for the 9.0 nm YIG/2.0 nm Au/4.3 nm Fe/6.1 nm Au structure, the YIG and Fe films were coupled by an interlayer exchange coupling, and the exchange coupled YIG exhibited an increased Gilbert damping compared to the bare YIG. This relationship between static and dynamic coupling provides direct evidence for spin pumping. The transfer of spin momentum across the YIG interface is surprisingly efficient with the spin mixing conductance g(↑↓) ≃ 1.2 × 10(14) cm(-2).
通过铁磁共振研究了铁磁绝缘体（YIG）/ 正常金属（Au）界面的自旋注入。通过比较裸 YIG 薄膜和覆盖 Au/Fe/Au 结构的 YIG 薄膜的 Gilbert 阻尼，确定了自旋混合电导。Au/Fe/Au 中的 Fe 层表现为自旋汇，与裸 YIG 相比，Gilbert 阻尼参数 α 增加。特别是对于 9.0nm YIG/2.0nm Au/4.3nm Fe/6.1nm Au 结构，YIG 和 Fe 薄膜通过层间交换耦合耦合，与裸 YIG 相比，交换耦合的 YIG 表现出增加的 Gilbert 阻尼。这种静态和动态耦合之间的关系为自旋泵浦提供了直接证据。自旋动量在 YIG 界面上的传递效率惊人，自旋混合电导 g(↑↓) ≃ 1.2×10(14)cm(-2)。
