Spin injection and detection up to room temperature in Heusler alloy/n-GaAs spin valves

Article

关键词: ELECTRICAL DETECTION;    HALL FACTOR;    TRANSPORT;    PRECESSION;   

DOI  :  10.1103/PhysRevB.94.235309

来源: SCIE

【 摘 要 】

We have measured the spin injection efficiency and spin lifetime in Co2FeSi/n-GaAs lateral nonlocal spin valves from 20 to 300 K. We observe large (similar to 40 mu V) spin valve signals at room temperature and injector currents of 10(3) A/cm(2), facilitated by fabricating spin valve separations smaller than the 1 mu m spin diffusion length and applying a forward bias to the detector contact. The spin transport parameters are measured by comparing the injector-detector contact separation dependence of the spin valve signal with a numerical model accounting for spin drift and diffusion. The apparent suppression of the spin injection efficiency at the lowest temperatures reflects a breakdown of the ordinary drift-diffusion model in the regime of large spin accumulation. A theoretical calculation of the D'yakonov-Perel' spin lifetime agrees well with the measured n-GaAs spin lifetime over the entire temperature range.

【 授权许可】

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