arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1802.09593cond-mat.mes-hall
收藏

室温钇铁石榴石薄膜中准声磁振子的自旋Seebeck效应和弹道输运

Spin Seebeck effect and ballistic transport of quasi-acoustic magnons in room-temperature yttrium iron garnet films

Timo Noack, Halyna Yu. Musiienko-Shmarova, Thomas Langner, Frank Heussner, Viktor Lauer, Björn Heinz, Dmytro A. Bozhko, Vitaliy I. Vasyuchka, Anna Pomyalov, Vic… 展开作者

Timo Noack, Halyna Yu. Musiienko-Shmarova, Thomas Langner, Frank Heussner, Viktor Lauer, Björn Heinz, Dmytro A. Bozhko, Vitaliy I. Vasyuchka, Anna Pomyalov, Victor S. L'vov, Burkard Hillebrands, Alexander A. Serga

摘要:

研究了不同厚度的镀铂钇铁石榴石(YIG)薄膜中纵向自旋塞贝克效应(LSSE)产生的自旋电流的瞬态行为。通过脉冲微波加热Pt层诱导LSSE,并使用相同层中的逆自旋霍尔效应电测量自旋电流。我们证明了LSSE的时间演化是由触发YIG/Pt界面附近热磁振子通量的热梯度的演化决定的。这些磁振子在YIG膜内以恒定的群速度弹道运动,而它们的数量在有效传播长度内呈指数衰减。能量在20 K以上的磁振子的弹道飞行是其几乎线性色散定律的结果,类似于声学声子。通过拟合随时间变化的LSSE信号,不同的膜厚度变化几乎一个数量级,我们发现,有效的传播长度实际上是独立的YIG膜厚度。我们认为这一事实的强有力的支持弹道输运方案-准声学磁振子在室温YIG的弹道传播。

英文摘要:

We studied the transient behavior of the spin current generated by the longitudinal spin Seebeck effect (LSSE) in a set of platinum-coated yttrium iron garnet (YIG) films of different thicknesses. The LSSE was induced by means of pulsed microwave heating of the Pt layer and the spin currents were measured electrically using the inverse spin Hall effect in the same layer. We demonstrate that the time evolution of the LSSE is determined by the evolution of the thermal gradient triggering the flux of thermal magnons in the vicinity of the YIG/Pt interface. These magnons move ballistically within the YIG film with a constant group velocity, while their number decays exponentially within an effective propagation length. The ballistic flight of the magnons with energies above 20K is a result of their almost linear dispersion law, similar to that of acoustic phonons. By fitting the time-dependent LSSE signal for different film thicknesses varying by almost an order of magnitude, we found that the effective propagation length is practically independent of the YIG film thickness. We consider this fact as strong support of a ballistic transport scenario - the ballistic propagation of quasi-acoustic magnons in room temperature YIG.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑