在共平面磁場中與Rashba 及Dresselhaus 自旋軌道交互作用之窄通道的量子傳輸

Quantum transport of narrow-channels in in-plane magnetic fields with Rashba and Dresselhaus spin-orbit interactions

張書瑜(Shu-Yu Chang)

指導教授 ： 鄭舜仁

國立交通大學/理學院/電子物理系所/碩士(2011年)

https://doi.org/10.6842/NCTU.2011.00172

摘要

我們研究考慮共平面磁場與Rashba及Dresselhaus自旋軌道交互作用之窄通道的同調量子傳輸。因為Rashba及Dresselhaus自旋軌道交互作用造成能帶水平方向的仳裂，而外加共平面磁場則造成能帶垂直方向的仳裂。首先，當我們同時考慮Rashba自旋軌道交互作用及共平面磁場時，能帶中，會出現虛能隙。在調變磁場大小的過程中，我們觀察電子自旋方向的改變。傳輸特性上，我們發現了似電子和似電洞的準束縛態。而當我們同時考慮共平面磁場與Rashba及Dresselhaus自旋軌道交互作用時，能帶開始變得不對稱。在傳輸特性上，除了發現似電子和似電洞的準束縛態之外，我們發現了Fano效應。因此，在考慮Rashba自旋軌道交互作用及共平面磁場時，Dresselhaus效應對傳輸特性有重大的影響。

關鍵字

自旋軌道交互作用 ； 量子傳輸

並列摘要

We investigate coherent electronic quantum transport in a narrow channel with Rashba and Dresselhaus spin-orbit interaction in the presence of an external in-plane magnetic field that is applied along the channel direction. The spin-split energy spectrum is horizontally shifted respectively by the Rashba and the Dresselhaus effects and is vertically shifted by the applied magnetic field. First, we consider the Rashba spin-orbit interaction and the in-plane magnetic field in the narrow channel, there is a pseudo-gap in the energy spectrum. With the increasing magnetic field, we investigate the variation of the spin orientation. Furthermore, we find the hole-like quasi bound state and electron-like quasi-bound state features in conductance. When we consider the Rashba, Dresselhaus and Zeeman effects simultaneously, energy spectrum becomes asymmetry. In some specific cases, except for the quasi-bound state feature, we find the Fano effect in transport properties. Hence, in the presence of the Rashba spin-orbit interaction and the in-plane magnetic field, the Dresselhaus effect significantly affects coherent magneto-quantum transport properties.

並列關鍵字

Rashba ； Dresselhaus ； quantum transport

參考文獻

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