Significant suppression of two-magnon scattering in ultrathin Co by controlling the surface magnetic anisotropy at the Co/nonmagnet interfaces
Significant suppression of two-magnon scattering in ultrathin Co by controlling the surface magnetic anisotropy at the Co/nonmagnet interfaces
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DOI：
10.1103/physrevb.106.174414
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发表时间：
2022-11-16
影响因子：
3.7
通讯作者：
Shiraishi，Masashi
中科院分区：
文献类型：
--
作者：
Yoshii，Shugo;Kato，Keisuke;Shiraishi，Masashi
为了抑制纳米厚Co层中的双磁振子散射（TMS）并实现低磁振子阻尼，研究了不同表面磁各向异性（SMA）能量的纳米晶Co层中的磁振子阻尼.我们验证了显着弱磁振子阻尼实现不同的播种层物种。虽然TMS在Cu和Al籽晶层上的CuCo中增强，但是在CuCo下方插入Ti籽晶层极大地抑制TMS，这归因于在Co和Ti之间的界面处的SMA的抑制。在Ti（3 nm）上的非晶Co层的吉尔伯特阻尼常数为0.020，与体Co的值相当，尽管此处的Co层厚度仅为2 nm。这种弱磁振子阻尼的实现可以打开可调谐磁振子激发的大门，从而使磁振子与其他量子（如光子）耦合，假定可以使用外部电场来调谐双磁铁磁体的磁化。
To enable suppression of two-magnon scattering (TMS) in nanometer-thick Co (ultrathin Co) layers and realize low-magnon damping in such layers, the magnon damping in ultrathin Co layers grown on various nonmagnetic seed layers with different surface magnetic anisotropy (SMA) energies are investigated. We verify the significantly weak magnon damping realized by varying the seeding layer species used. Although TMS is enhanced in ultrathin Co on Cu and Al seeding layers, the insertion of a Ti seeding layer below the ultrathin Co greatly suppresses the TMS, which is attributed to suppression of the SMA at the interface between Co and Ti. The Gilbert damping constant of the ultrathin Co layer on Ti (3 nm), 0.020, is comparable to the value for bulk Co, although the Co layer thickness here is only 2 nm. Realization of such weak magnon damping can open the door to tunable magnon excitation, thus enabling coupling of magnons with other quanta such as photons, given that the magnetization of ultrathin ferromagnets can be tuned using an external electric field.