標題: 二維cubic-k Dresselhaus-type 電子系統中在圓盤附近的量子散射
QUANTUM SCATTERING FROM A CIRCULAR DISK IN A CUBIC-K DRESSELHAUS-TYPE TWO DIMENSIONAL ELECTRON GAS
作者: 杜冠誼
朱仲夏
電子物理系所
關鍵字: 自旋電子學;Dresselhaus自旋軌道耦合;量子散射;自旋電流;spintronics;Dresselhaus spin-orbit coupling;quantum sacttering;spin current
公開日期: 2008
摘要: 此論文的工作一直致力解讀在一個圓盤微結構附近,考慮Dresselhaus 型自 旋軌道耦合作用下自旋相關的散射效應。Dresselhaus 型自旋軌道耦合作用在這 裡主要包括了linear-k 相關以及cubic-k 相關的貢獻。 以分波方法為基礎,在散射區間內經計算後可以得到完整散射後的波函數。 透過調查入射電子平面波後,DSOI 造成空間辦別的散射效應,linear-k 與cubic-k DSOI 貢獻的差異可以明顯地被辨識,同時得到所對應的能量耗散關係。在我們的發 現:對於linear-k Dresselhaus,電子自旋密度與機率密度分佈擁有空間對稱性 輪廓,與平面波入射角度無關。相反地,在cubic-k Dresselhaus SOI 例子中明顯 地表示出與平面波入射角度相關。 特別地,若入射平面波角度為幾個特定的角度,我們可以發現有相似的電子 自旋密度對應在cubic-k Dresselhaus 例子與linear-k Dresselhaus 例子之 間。
This thesis work has devoted to the study of spin-dependent scattering e®ects from a circular-disk microscopic structure with Dresselhaus-type spin-orbit coupling. The Dres- selhaus spin-orbit coupling considered here includes both contributions terms for one is linear-k dependence and the other is cubic-k dependence. Based on the method of partial waves, the complete scattering wave function in a circular scattering region can be rigorously derived and obtained. Through investigating their spatial-resolved scattering behaviors from linear and cubic Dresselhaus-type SOI disk under the electron plane wave incidence, di®erent DSOI contributions can be appar- ently discerned, and their corresponding detail energy dispersion relationships as well. In our ‾ndings: for linear-k Dresselhaus case, the spin density and probability density distri- butions own their spatial symmetry pro‾le, which is featured independence of the plane wave incident angle. On the contrary, strong incident angle dependence is manifested for the case of cubic-k Dresselhaus spin-orbit interaction. In particular , for incidence plane wave in some characteristic angle, we can ‾nd similar spin density responses between cubic-k Dresselhaus case and linear-k Dresselhaus case.
URI: http://140.113.39.130/cdrfb3/record/nctu/#GT079621548
http://hdl.handle.net/11536/42462
Appears in Collections:Thesis


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