本論文研究電流在一個兩端彎曲的石墨烯奈米帶傳輸性質，鋸齒型石墨烯奈米帶(ZGNR)位於兩個扶手椅形石墨烯奈米(AGNR)中間 。在簡介石墨烯和帶狀的石墨烯(GNR)後，我們用緊束縛近似模型來建立A-Z-AGNR系統，修改T. Ando提出的迭代方法和邊界條件，並企圖建立更有計算彈性(flexible)的程式。我們在ZGNR上設置側向電場，模擬不同條件下的電流。結果顯示適當的側向電場可以將電流關掉，達到場效控制元件的目的。另外，改變側向電場、ZGNR長度和入射電子態能量，穿透電流會隨之振盪，原因可能是相干傳輸電子態在ZGNR內多重反射，當滿足建設性干涉條件時，發生共振穿遂。

We investigate theoretically the transport current through a double-bended graphene nanoribbon where ZGNR is set between two AGNR leads. After the introduction of graphene and graphene nanoribbon, we use the tight-binding model to describe an A-Z-AGNR system and then modify both the recursive green function method and the boundary conditions proposed by T. Ando to suit our study. We develop a program which is capable of flexible calculation. We simulate currents under different conditions, with a lateral electric field applied on the portion of ZGNR. The results suggest that the appropriate lateral electric field could turn off the current and the device could be controlled by field effect. The transmission oscillates when changing the lateral electric field, the length of ZGNR, and the energy of incident electron. This oscillation is due to the coherent resonant tunneling, which happens when the propagating electron bounces back and forth between the two ends of ZGNR and satisfies the constructive interference condition.

[1]A.H. Castro Neto,F. Guinea,N. M. R. Peres,K.S. Novoselov,and A.K. Geim,Rev. Mod. Phys. 81 ,109(2009).
[2] K.S. Novoselov et al.,Science 306,666-669(2004).
[3] P. Avouris ,Z. Chen, and V. Perebeinos, “Carbon-based electronics”,Nature Nanotechnology 2, 605-615(2007).
[4] G. W. Semenoff ,Phys. Rev. Lett. 53,2449(1984).
[5]A.K. Geim,”Graphene: Status and Prospects”.,Science 324,1530-1534(2009).
[6]J.J. Palacios,J. Fernndez-Rossier,L. Brey, H.A. Fertig,Semicond. Sci. Technol. 25,033003(2010).
[7] ]Z.Z. Zhang,K. Chang,and K.S. Chan,Appl. Phys. Lett. 93,062106(2008).
[8]F. Schwierz,Nature Nanotech. 5,487-496(2010).
[9] D. S. L. Abergel, V. Apalkov, J. Berashevich, K. Ziegler,and T. Chakraborty,Adv. Phys. 59 ,261-482(2010).
[10] Young-Woo Son ,Marvin L. Cohen and Steven G. Louie,Nature 444,347~349(2006) .
[11] ]D.S. Novikov ,Phys. Rev. Lett. 99,056802(2007).
[12] ]K. Majumdar, K. V. R. M. Murali, N. Bhat, and Y.-M. Lin, Nano Lett. 10,
2857 (2010).
[13]T. Ando,Phys. Rev. B 44,8017(1991).