二維cubic-k Dresselhaus-type 電子系統中在圓盤附近的量子散射

Abstract

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.