Orientation of electron spins in hybrid ferromagnet–semiconductor nanostructures
Orientation of electron spins in hybrid ferromagnet–semiconductor nanostructures
复制标题
混合铁磁体-半导体纳米结构中电子自旋的方向
DOI：
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
M. Bayer
中科院分区：
文献类型：
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作者：
I. Akimov;V. L. Korenev;V. F. Sapega;L. Langer;S. Zaitsev;Yu. A. Danilov;D. Yakovlev;M. Bayer
研究了铁磁体（FM）-半导体（SC）混合结构中电子的自旋取向，该混合结构由（Ga，Mn）As铁磁层组成，该铁磁层直接放置在非磁性SC（In，Ga）As量子阱（QW）附近。结果表明，SC量子阱中载流子的极化是通过自旋相关隧穿进入磁化铁磁层来实现的。这导致电子的动态自旋极化，这可以通过时间分辨光致发光直接观察到。我们发现，电子自旋极化增长的时间激发后的光脉冲，并可能达到高达30%的值。自旋相关捕获的速率随着铁磁层和QW之间的间隔层厚度的减小而呈指数陡峭地增长，并且其持续到（Ga，Mn）As层的居里温度。从时间分辨的泵浦-探测克尔旋转数据，我们评估了由于与铁磁（Ga，Mn）As层的相互作用而导致的电子塞曼子能级之间的能量分裂的值仅为几μ eV，这表明平衡自旋极化可以忽略不计。
The spin orientation of electrons is studied in ferromagnet (FM)–semiconductor (SC) hybrid structures composed of a (Ga,Mn)As ferromagnetic layer, which is placed in the direct vicinity of a non‐magnetic SC (In,Ga)As quantum well (QW). It is shown that the polarization of carriers in the SC QW is achieved by spin‐dependent tunnelling into the magnetized ferromagnetic layer. This leads to dynamical spin polarization of the electrons, which can be directly observed by means of time‐resolved photoluminescence. We find that the electron spin polarization grows in time after excitation with an optical pulse and may reach values as large as 30%. The rate of spin‐dependent capture grows exponentially steeply with decreasing thickness of the spacer between ferromagnetic layer and QW, and it persists up to the Curie temperature of the (Ga,Mn)As layer. From time‐resolved pump–probe Kerr rotation data, we evaluate a value of only a few μ eV for the energy splitting between the electron Zeeman sublevels due to interaction with the ferromagnetic (Ga,Mn)As layer, indicating that the equilibrium spin polarization is negligible.
混合自旋注入器件中居里温度的邻近诱导增强
影响因子：
8.6
作者：
C. Song;M. Sperl;M. Utz;M. Ciorga;G. Woltersdorf;D. Schuh;D. Bougeard;C.H. Back;D. Weiss
通讯作者：
D. Weiss