Ferromagnetic imprinting of nuclear spins in semiconductors

被引：114

作者：

Kawakami, RK

Kato, Y

Hanson, M

Malajovich, I

Stephens, JM

Johnston-Halperin, E

Salis, G

Gossard, AC

Awschalom, DD ^{[1
]}

机构：

[1] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93106 USA

[2] Univ Calif Santa Barbara, Dept Mat, Santa Barbara, CA 93106 USA

来源：

SCIENCE | 2001年 / 294卷 / 5540期

关键词：

D O I：

10.1126/science.1063186

中图分类号：

O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];

学科分类号：

07 ; 0710 ; 09 ;

摘要：

We examine how a ferromagnetic layer affects the coherent electron spin dynamics in a neighboring gallium arsenide semiconductor. Uttrafast optical pump-probe measurements reveal that the spin dynamics are unexpectedly dominated by hyperpolarized nuclear spins that align along the ferromagnet's magnetization. We find evidence that photoexcited carriers acquire spin-polarization from the ferromagnet, and dynamically polarize these nuclear spins. The resulting hyperfine fields are as high as 9000 gauss in small external fields (less than 1000 gauss), enabling ferromagnetic control of local electron spin coherence.

引用

页码：131 / 134

页数：4