矽鍺type-II多重量子井中自旋載子的生成

Spin generation in type-II SiGe/Si multiple quantum wells

蕭鴻齊(Hung-Chi Hsiao)

指導教授 ： 陳永芳

國立臺灣大學/理學院/物理研究所/碩士(2009年)

https://doi.org/10.6342/NTU.2009.10476

摘要

在本論文中，我們將介紹兩個自旋載子的生成方式，即圓偏振光激發電流(circular photogalvanic effect, CPGE)與自旋霍爾效應(spin Hall effect, SHE)。

在第一部分中，我們將探討入射光角度與內建電場大小對CPGE的影響。此外，我們還探討了樣品本身折射率在入射角與CPGE的關係中扮演什麼樣的角色；以及type-II能帶結構中，入射光在強度不大的時候對CPGE有增強的效果。

在第二部分中，我們將探討type-II Si0.5Ge0.5/Si 多重量子井中的自旋霍爾效應是否存在，以及圓偏振螢光測量法在這個樣品的數據分析。

關鍵字

自旋

並列摘要

In this thesis, we report two methods of the spin current generation in type-II Si0.5Ge0.5/Si multiple quantum wells.

In the first part of this thesis, we report the relationship between the magnitude of built-in electric field and the circular photogalvanic effect (CPGE). It is found that the type-II band alignment makes the CPGE very sensitive to the power of incident radiation. We also report the influence of refractive index on the relationship between the angle of incident radiation and CPGE.

In the second part of this thesis, we show the existence of spin Hall effect (SHE) in Si0.5Ge0.5/Si multiple quantum wells and give an improved method to analyze the SHE because the variation of the detected signal with the direction of polarization consists of the contribution of non-phonon and phonon-assisted processes.

並列關鍵字

spin ； CPGE ； spin Hall effect

參考文獻

34. Z. Zhang, R. Zhang, B. Liu, Z. L. Xie, X. Q. Xiu, P. Han, H. Lu, Y. D. Zheng, Y. H. Chen, C. G. Tang, and Z. G. Wang, Solid State Commun. 145, 159 (2008).

24. C. L. Yang, H. T. He, Lu Ding, L. J. Cui, Y. P. Zeng, J. N. Wang, and W. K. Ge, Phys. Rev. Lett. 96, 186605 (2006).

31. K. S. Cho, C. T. Liang, Y. F. Chen, Y. Q. Tang, and B. Shen, Phys. Rev. B 75, 085327 (2007).

10. H. J. Chang, T. W. Chen, J. W. Chen, W. C. Hong, W. C. Tsai, Y. F. Chen, and G.Y. Guo, Phys. Rev. Lett. 98, 136403 (2007).

25. H. J. Chang, T. W. Chen, J. W. Chen, W. C. Hong, W. C. Tsai, Y. F. Chen, and G. Y. Guo, Phys. Rev. Lett. 98, 136403 (2007).