Optical polarization of nuclear spins in GaAs
Optical polarization of nuclear spins in GaAs
复制标题
GaAs 中核自旋的光学偏振
DOI：
10.1103/physrevb.69.075203
复制
发表时间：
2004
影响因子：
3.7
通讯作者：
J. Reimer
中科院分区：
文献类型：
--
作者：
A. Paravastu;S. Hayes;B. Schwickert;L. Dinh;M. Balooch;J. Reimer
测量了9.4T下半绝缘GaAs的激光增强NMR谱的光子能量、辐照时间和样品温度的依赖关系。这些数据被用来测试现有的模型的机制，光学核极化-即，浅施主态的光激发和随后的自旋扩散的极化在整个散装。目前的结果的特点，如它们的独特性，半绝缘GaAs和泵浦数据通过激光照射以上的带隙，是不符合这个模型。提出了一个额外的模型，包括本地化的顺磁中心作为电子自旋极化的存储站点，但依赖于离域电子状态来完成体核自旋极化。离域态可以是自由激子。
The photon energy, irradiation time, and sample temperature dependences of laser-enhanced NMR spectra from semi-insulating GaAs at 9.4 T were measured. These data were used to test the existing model for the mechanism of optical nuclear polarization---namely, optical excitation of shallow donor states and subsequent spin diffusion of polarization throughout the bulk. Features of the present results, such as their uniqueness to semi-insulating GaAs and pumping data obtained via laser irradiation above the band gap, are inconsistent with this model. An additional model is proposed that includes localized paramagnetic centers as storage sites for electron spin polarization, but relies upon delocalized electron states to accomplish the bulk nuclear spin polarizations. The delocalized states could be free excitons.
影响因子：
8.6
作者：
Kikkawa, JM;Awschalom, DD
通讯作者：
Awschalom, DD