在石墨烯中實現量子自旋霍爾效應是自旋電子學的基礎和技術研究重點之一。然而，源自高度對稱性的六邊形sp2鍵結和單一元素的結構妨礙了自旋軌道耦合的產生。為了提高石墨烯中的自旋軌道耦合，許多研究提供了不同的實驗方式，例如重原子吸附和過渡金屬二硫屬化物的鄰近效應。
在這次的研究我們通過乾式二維材料轉印技術展現了在石墨烯 / 拓樸絕緣體Bi2Se3 異質結構中的電性傳輸量測。我們期望可以觀測到自旋軌道耦合引起的現象，同時保持其高載子遷移率。在此次實驗中，我們在石墨烯 / Bi2Se3 異質結構中觀察到石墨烯弱局域效應抑制的現象，這是拓撲絕緣體表面態通過鄰近效應引出石墨烯的自旋軌道相互作用的跡象，正如之前的理論研究所提出的。
為了進一步提高樣品中拓樸絕緣體的品質，我們開發了一種封裝結構的 Via-method 元件，該元件是以六方氮化硼 / 石墨烯 / 拓樸絕緣體做序列堆疊，來進一步減少製程化學殘留物和外界大氣的影響。這種元件結構對研究各種鄰近效應及其在量子元件開發擁有廣闊的前景。雖然在這種樣品到目前為止我們沒有觀察到任何與自旋軌道耦合相關的信號，但我們在此元件量測到類似量子霍爾效應的信號，證明這種異質結構的品質是可以保證的。為了研究鄰近效應引起的自旋軌道耦合，我們正在尋找任何實驗方法來對齊石墨烯和拓樸絕緣體之間的化學勢。

Realization of the quantum spin Hall effect in graphene is one of the research focuses in spintronic for both fundamental and technological purposes. However, the high symmetric consideration originating from the hexagonal sp2 bonding and single element configuration block the generation of spin-orbit coupling (SOC). To enhance SOC in graphene, numerous works have provided different manners, such as heavy adatom absorption, and proximity effect of transition metal dichalcogenides.
Here, we report on the electrical transport in graphene / topological insulator Bi2Se3 heterostructure by dry pick-up and transfer techniques. We plan to investigate phenomena induced by spin-orbit coupling while remaning its high mobility. In this device, we observed suppression of weak–localization in this graphene / Bi2Se3 heterostructure, a sign of induced spin-orbit interaction by proximity effect via topological insulator (TI) surface state, as previous work proposed.
In order to increase surface state of TI’s quality, we developed an encapsulated Via-method device, which is stacking in hexagonal boron nitride (hBN) / graphene / TI sequence, to further minimize the influence from fabrication residue and ambient air. This device structure may hold great promise to study all kinds of proximity effects and its implication in quantum devices and technologies. Though we didn’t observe any signals refers to the spin-orbit coupling so far, we observed quantum Hall effect (QHE)-like signal in such devices, indicating the high quality of this heterostructure. To investigate SOC by proximity effect, we were searching for methods to align chemical potential between graphene and TI.

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