论文标题
石墨烯量子点中的可调谷拆分和双极操作
Tunable valley splitting and bipolar operation in graphene quantum dots
论文作者
论文摘要
石墨烯中的量子状态是四倍变化：旋转两倍，在山谷中有两个倍。自由度可以用于量子制剂。在我们的双层石墨烯量子量表中，我们证明，谷g-factorgv类似地定义为旋转的g-factorgsforvalley在垂直磁场中分布的旋转g-factorgsForvalley可调节4个以上的20倍以上，从20到90倍以上。从较大的电子点上，可以根据能量来确定的较大的电量，从而使较大的电源量均能达到较大的能量。允许调整点铅隧道耦合。在我们的多功能设备上，双极操作可以执行我们的量子dotwith荷载载流子或与导线相同的极性。通过柱塞门的作用，极性的点可以调节到第一个电荷载体，从而可以观察到从电子到孔点的thetransition。通过添加更多的门，该系统可以扩展到托管双点。
Quantum states in graphene are four-fold degenerate: two fold in spins, and two fold in valleys.Both degrees of freedom can be utilized for qubit preparations. In our bilayer graphene quantumdots, we demonstrate that the valley g-factorgv, defined analogously as the spin g-factorgsforvalley splitting in perpendicular magnetic field, is tunable by over a factor of 4 from 20 to 90. Wefind that largergvresults from larger electronic dot sizes, determined from the charging energy.This control is achieved by adjusting voltages on merely two gates, which also allows for tuning ofthe dot-lead tunnel coupling. On our versatile device, bipolar operation, charging our quantum dotwith charge carriers of the same or the opposite polarity as the leads, can be performed. Dots ofboth polarity are tunable to the first charge carrier by action of the plunger gate, such that thetransition from an electron to a hole dot can be observed. By adding more gates, this system caneasily be extended to host double dots.
