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arXiv 1912.02136cond-mat.mes-hall
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双量子点自旋阀

A Double Quantum Dot Spin Valve

Arunav Bordoloi, Valentina Zannier, Lucia Sorba, Christian Schönenberger, Andreas Baumgartner

摘要:

自旋电子学中最基本和长期的目标是电调谐高效的自旋注入器和检测器,优选地与纳米级电子器件兼容。在这里,我们证明了所有这些点使用半导体量子点(QD),单独自旋极化的铁磁分裂栅(FSG)。作为原理的证明,我们制造了一个双量子点自旋阀组成的两个弱耦合的半导体量子点在InAs纳米线(NW),每个独立的FSG,可以被磁化平行或反平行。在零外磁场下的隧穿磁电阻(TMR)实验中,我们发现两种反平行结构的自旋阀电导大大降低,量子点极化为$\sim 27\%$ .通过小的外部场和优化的栅极电压可以显著改善TMR,这导致在$+80\%$和$-90\%$之间的连续电可调谐的TMR。一个简单的模型定量再现了我们的所有研究结果,表明门可调量子点极化的$\pm 80\%$。这种通用的自旋极化量子点适用于各种应用,例如在各种纳米电子学实验中的自旋投影和相关实验。

英文摘要:

A most fundamental and longstanding goal in spintronics is to electrically tune highly efficient spin injectors and detectors, preferably compatible with nanoscale electronics. Here, we demonstrate all these points using semiconductor quantum dots (QDs), individually spin-polarized by ferromagnetic split-gates (FSGs). As a proof of principle, we fabricated a double QD spin valve consisting of two weakly coupled semiconducting QDs in an InAs nanowire (NW), each with independent FSGs that can be magnetized in parallel or anti-parallel. In tunneling magnetoresistance (TMR) experiments at zero external magnetic field, we find a strongly reduced spin valve conductance for the two anti-parallel configurations, with a single QD polarization of $\sim 27\%$. The TMR can be significantly improved by a small external field and optimized gate voltages, which results in a continuously electrically tunable TMR between $+80\%$ and $-90\%$. A simple model quantitatively reproduces all our findings, suggesting a gate tunable QD polarization of $\pm 80\%$. Such versatile spin-polarized QDs are suitable for various applications, for example in spin projection and correlation experiments in a large variety of nanoelectronics experiments.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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