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arXiv 1301.4572cond-mat.mes-hallcond-mat.mtrl-sci
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回旋共振下狄拉克费米子系统中的巨自旋极化电流

Giant spin-polarized current in a Dirac fermion system at cyclotron resonance

P. Olbrich, C. Zoth, P. Vierling, K. -M. Dantscher, G. V. Budkin, S. A. Tarasenko, V. V. Bel'kov, D. A. Kozlov, Z. D. Kvon, N. N. Mikhailov, S. A. Dvoretsky, S. D. Ganichev

摘要:

本文报道了在临界厚度的HgTe/HgCdTe量子阱中观测到的巨大自旋极化光电流,在临界厚度处出现狄拉克谱。用太赫兹辐射和扫频磁场激发6.6 nm宽的量子阱,我们探测到了共振光电流。值得注意的是,共振的位置可以通过光学选通从负(-0.4 T)到正(高达1.2 T)磁场调谐。光电流数据、辐射透射率测量以及Shubnikov-de Haas效应和量子霍尔效应的测量,证明了光电流的增强是由狄拉克费米子系统中的回旋共振引起的。该理论表明,电流是自旋极化的,起源于辐射加热的载流子的自旋相关散射。

英文摘要:

We report on the observation of the giant spin-polarized photocurrent in HgTe/HgCdTe quantum well (QW) of critical thickness at which a Dirac spectrum emerges. Exciting QW of 6.6 nm width by terahertz (THz) radiation and sweeping magnetic field we detected a resonant photocurrent. Remarkably, the position of the resonance can be tuned from negative (-0.4 T) to positive (up to 1.2 T) magnetic fields by means of optical gating. The photocurent data, accompanied by measurements of radiation transmission as well as Shubnikov-de Haas and quantum Hall effects, give an evidence that the enhancement of the photocurrent is caused by cyclotron resonance in a Dirac fermion system. The developed theory shows that the current is spin polarized and originates from the spin dependent scattering of charge carriers heated by the radiation.

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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