電晶體於 1957 年被 Shockly、Bardeen 和 Brattain 發明，隨著時間的演進，電晶體尺寸的微縮，操作電壓與功率耗損逐漸微縮下降，電晶體的尺寸已進入了奈米的尺度。昔日長久以來不斷地微縮光罩尺寸，原先``由上而下'' (top-down) 的製程概念，漸漸地因製成的極限遇到了瓶頸，近來因而轉換為 ``由下而上'' (bottom-up) 的概念，直接使用先天上奈米尺度的材料來製作元件，材料介的新寵兒奈米碳管 (carbon nanotubes)、奈米線 (nanowires) 都是先天上很好奈米尺度的材料。本論文中的元件，將引用奈米碳管做為元件的通道，以取代電子反轉層 (Inversion layer) 在以往場效電晶體 (MOSFET) 的通道的角色。傳統場效電晶體中，以閘極 (Gate) 電壓來控制橫向電場的電流，電荷的流動來分辨元件的導通或關閉，一直忽略了電子的另一自由度 ``自旋'' (Spin)；電子擁有自旋向上 (Spin up) 與自旋向下 (Spin down) 兩種，在加磁場施予下磁性材料中的電子被極化成單一方向，注入於通道中，藉此利用辨識自旋的方向重新定義元件的開關。

利用奈米碳管做為通道，研究電子自旋傳輸始於 1999 年，多數的研究以鈷鎳或鎳鐵合金等磁性金屬做為電極，注入極化電子。本論文則用奈米碳管優良的傳輸特性與提高通道電子自旋極化率的單自旋金屬\cro 電極結合，這是前所未見的實驗。首章初談磁性材料與奈米碳管的特性，第二章介紹自旋電子學，包含磁阻、自旋散射、單自旋金屬、自旋極化率以及自旋傳輸，第三章介紹實驗的製成步驟，第四章是成長出\cro 薄膜的特性測量與自旋元件的量測，第五章為結論。

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