Gate control of dynamic nuclear polarization in GaAs quantum wells.
Gate control of dynamic nuclear polarization in GaAs quantum wells.
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DOI：
10.1103/physrevlett.94.097601
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发表时间：
2005-03
影响因子：
8.6
通讯作者：
H. Sanada;S. Matsuzaka;Ken Morita;C. Hu;Y. Ohno;H. Ohno
中科院分区：
文献类型：
--
作者：
H. Sanada;S. Matsuzaka;Ken Morita;C. Hu;Y. Ohno;H. Ohno
通过时间分辨克尔旋转测量，在肖特基栅控的n - GaAs/AlGaAs（110）量子阱中展示了光取向下动态核极化的栅极控制。当施主诱导的背景电子密度从金属态降低到绝缘态时，由于超精细相互作用之外的机制导致的电子自旋弛豫被有效抑制。随后光激发电子自旋的积累显著增强了低磁场下的动态核极化，使我们能够通过外部栅极电压调节核自旋极化。
Gate control of dynamic nuclear polarization under optical orientation is demonstrated in a Schottky-gated n-GaAs/AlGaAs (110) quantum well by time-resolved Kerr rotation measurements. Spin relaxation of electrons due to mechanisms other than the hyperfine interaction is effectively suppressed as the donor induced background electron density is reduced from metallic to insulating regimes. Subsequent accumulation of photoexcited electron spins dramatically enhances dynamic nuclear polarization at low magnetic field, allowing us to tune nuclear spin polarization by external gate voltages.