在本實驗中使用氫離子蝕刻的方式，在拓樸絕緣體Bi2Se3薄膜上形成Bi bilayer，再透過自旋幫浦機制，研究Bi bilayer對整體產生電壓的影響，並透過加入銅插層的方式，做一系列的實驗與討論。
首先透過PLD系統成長鎳鐵薄膜，透過鐵磁共振的量測，確認其在室溫下成長依舊具有良好的鐵磁性。將MBE所成長的Bi2Se3薄膜蓋上保護層後，在PLD中進行去保護層及氫化，便成長鐵磁層鎳鐵以及改善傳輸性質暨保護層銅，以無氫化、氫化、氫化成長1奈米銅、氫化成長3奈米銅，做一系列的自旋幫浦量測，並對其做進一步討論。
在上述的四組樣品中，本實驗皆有量測到自旋幫浦所產生電壓訊號，在扣除異常霍爾效應所產生的電壓，有Bi bilayer(反轉Rashba-Edelstein 效應)所得到訊號相較於單純Bi2Se3薄膜(反轉自旋霍爾效應)來的大，推測Bi bilayer的形成確實有效的提升了自旋幫浦的轉換效率，而在不同厚度中，皆在插入銅一奈米的情況下量測到最大的電壓訊號，此外透過自旋混和電導以及自旋流密度的計算，說明了銅確實有效地的改善自旋混和電導，進而提升注入自旋流密度，且銅亦可保護鐵磁層直接與拓樸絕緣體直接接觸而破壞其性質。而在本實驗中，透過比較各組樣品的量測數據，並加以計算後，得到Bi bilayer的轉換效率為0.2~0.6奈米。

Ultrathin bilayers of bismuth have been predicated to be two-dimensional (2D) topological insulators (TI). In our experiment, we use a top-down approach to prepare uniform and well ordered Bi (111) BL with deliberate hydrogen etching on epitaxial Bi2Se3 films. A large Rashba splitting with a coupling constant of ～4.5 eV．Å is attributed to the large spin-orbit coupling (SOC) and interface potential gradient between Bi (111) BL and Bi2Se3.
Spin pumping is a mechanism that generates spin currents from ferromagnetic metal(FM) and injects into normal metal(NM), while we can detect ISHE(Inverse spin Hall effect) or IREE(Inverse Rashba Edelstein effect) voltage signal in the NM layer. In our system, Bi2Se3 grown on c-plane sapphire by MBE and then prepare Bi BL by hydrogen etching. We measured the IREE/ISHE via spin pumping in Bi2Se3、Bi2Se3/ Bi BL、Bi2Se3/ Bi BL/Cu(1nm) and Bi2Se3/ Bi BL/Cu(3nm). The spin current is injected from the ferromagnetic resonance of a NiFe layer (by PLD) towards the Rashba interface/TI surface, where it is further converted into a charge current.
Compare the Bi2Se3、Bi2Se3/ Bi BL two samples, the charge signal is much smaller with only Bi2Se3, the spin-to-charge conversion can be unambiguously ascribed to the Rashba coupling at Bi BL Rashba interface. In addition, in our experiment the spin mixing conductance can improved by Cu layer between NM/FM. It also can protect Rashba interface from the destroyed by FM. Using spin pumping theory, we quantify the conversion parameter of spin to charge current is 0.2~0.6nm. According to our data, the IREE at Rashba interface can be used for efficient charge-spin conversion in spintronics.

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