Gate-voltage control of spin interactions between electrons and nuclei in a semiconductor
Gate-voltage control of spin interactions between electrons and nuclei in a semiconductor
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DOI：
10.1038/415281a
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发表时间：
2002-01-17
期刊：
影响因子：
64.8
通讯作者：
von Klitzing, K
中科院分区：
文献类型：
--
作者：
Smet, JH;Deutschmann, RA;von Klitzing, K
半导体在电子器件中无处不在，因为其电荷分布可以通过电压方便地进行操控以执行逻辑运算。对电子或原子核的自旋自由度实现类似程度的控制，可能为信息处理和基础固态物理问题的研究提供有趣的前景。在此我们报道了一些操作过程，这些过程仅使用栅极电压就在局限于二维且处于垂直磁场中的电子与主体半导体的原子核之间实现了自旋角动量的受控转移。我们表明，在电子系统的铁磁基态附近，自旋转移速率可以提高，并且诱导的核自旋极化随后可以被存储和“读出”。这些技术还可以组合成一种光谱工具，用于检测电子系统中促进自旋转移的低能集体激发。这种激发的存在取决于适当的电子 - 电子关联，并且可以通过例如通过栅极电压改变电子密度来对其进行调节。
Semiconductors are ubiquitous in device electronics, because their charge distributions can be conveniently manipulated with voltages to perform logic operations. Achieving a similar level of control over the spin degrees of freedom, either from electrons or nuclei, could provide intriguing prospects for both information processing and the study of fundamental solid-state physics issues. Here we report procedures that carry out the controlled transfer of spin angular momentum between electrons-confined to two dimensions and subjected to a perpendicular magnetic field-and the nuclei of the host semiconductor, using gate voltages only. We show that the spin transfer rate can be enhanced near a ferromagnetic ground state of the electron system, and that the induced nuclear spin polarization can be subsequently stored and 'read out'. These techniques can also be combined into a spectroscopic tool to detect the low-energy collective excitations in the electron system that promote the spin transfer. The existence of such excitations is contingent on appropriate electron-electron correlations, and these can be tuned by changing, for example, the electron density via a gate voltage.