控制及操作自旋電子是自旋電子學的要點。在自旋電子旋中，主要利用自旋方向而非電子，來傳遞訊息。由於特殊的物理現象，過渡金屬硫族化合物提供一個新的平台使得自旋電子與電子的其他自由度有交互作用，並且被用來作為新的自旋電子學的應用。相較於石墨烯，二硫化鉬有一個來自於重金屬原子的 d 軌域，導致材料本身有很強的自旋軌道交互作用，因而提供一個平台使得我們可以探索自旋電子學的物理現象及應用。
此篇論文中，我們使用非局域性量測放在二氧化矽和矽基板，以機械剝離法製作的二硫化鉬 。此外，我們使用電子束蝕刻技術定義一個可調控長度的霍爾電極。在不同長度的霍爾電極中的量測結果中所顯示的負電阻現象，此現象可能來自於類彈道傳輸傳輸機制及自旋霍爾效應。為了進一步確認結果，我們引入平行磁場來進一步的探討及研究。

The control and manipulation of the electron spin in semiconductors is central to spin- tronics, which aims to represent digital information using spin orientation rather than electron charge. Due to the unique physical characteristics, transition metal dichalco- genides (TMDCs) have provided new platforms to probe the spin interaction with other degrees of freedom for electrons, as well as to be used for novel spintronics applications. Molybdenum disulphide(MoS2) has a strong spin-orbit coupling (SOC) originated from the d orbitals of the heavy metal atoms, and can be an interesting platform to explore spin physics and spintronics applications absent in graphene due to its extremely small SOC.
Here, we report non-local electrical measurements in MoS2. The experimental data were obtained for MoS2 after mechanical exfoliation on top of SiO2/Si wafers. In addition, we define a tunable Hall bar structure using E-beam lithography. The result shows a negative resistance as we detect in a different length of tunable Hall bars. Based on this results, a nonlocal electric response in the different regime of the device, is argued to be resulting from the quasiballistic transport mechanism or spin Hall effect(SHE). And thus, the sweeping of an in-plane magnetic filed B|| was applied to confirm whether there is spin diffusion mediating charge conduction in MoS2.

[1] B. Radisavljevic et al. Nature Nanotech., 6, 147150 (2011).
[2] Zhike Liu et al. Chem. Soc. Rev., 44, 5638 (2015).
[3] Lorenz Meier et al. Nature Phys., 3, 650 - 654 (2007).
[4] Wei Han et al. Nature Nanotech., 9, 794807 (2014).
[5] Y. Shimazaki et al. Nature Phys., 11, 10321036 (2015).
[6] Filippo Pizzocchero et al. Nat. Commun., 7, 11894 (2016).
[7] G. Mihajlovic et al. Phys. Rev. Lett., 103, 166601(2009).
[8] Branimir Radisavljevic and Andras Kis. Nat. Mater., 12, 815-820 (2013).
[9] Kin Fai Mak et al. Phys. Rev. Lett., 105, 136805 (2010).
[10] Qing Hua Wang et al. Nature Nanotech., 7, 699712 (2012).
[11] John Schliemann et al. Phys. Rev. Lett., 90, 146801 (2003).
[12] H. Ochoa et al. Phys. Rev. Lett., 108, 206808(2012).
[13] Jieun Lee et al. Nature Nanotech., 11, 421425 (2016).
[14] K.S. Novoselov et al. Science, 306, 666-669 (2004).
[15] Hong Li et al. Adv. Funct. Mater., 22, 13851390 (2012).
[16] Stephen McDonnell et al. Apl. Mater., 8, 82898294 (2016).
[17] Han Liu et al. Acs Nano, 6, 85638569 (2012).
[18] Andreas V. Stier et al. Nature. Commu., 7, 10643(2016).
[19] Jieun Lee et al. Nature Nanotech., 11, 421425 (2016).