论文标题
双层石墨烯量子点中电荷态的分散感
Dispersive sensing of charge states in a bilayer graphene quantum dot
论文作者
论文摘要
我们证明了在双层石墨烯中的栅极定义的少数电子量子点中对单个电荷状态的分散读数。我们采用射频反射测定电路，其中具有谐振频率接近280 MHz的LC谐振器直接与量子点设备的欧姆接触耦合。基于量子电容的变化的检测方案在宽门电压范围内运行，并允许探测激发的状态至单电子状态。至关重要的是，提出的感应技术避免使用其他电容耦合的量子设备，例如量子点接触或单电子晶体管，从而使色散感测对于栅极定义的石墨烯量子点特别有趣。
We demonstrate dispersive readout of individual charge states in a gate-defined few-electron quantum dot in bilayer graphene. We employ a radio frequency reflectometry circuit, where an LC resonator with a resonance frequency close to 280 MHz is directly coupled to an ohmic contact of the quantum dot device. The detection scheme based on changes in the quantum capacitance operates over a wide gate-voltage range and allows to probe excited states down to the single-electron regime. Crucially, the presented sensing technique avoids the use of an additional, capacitively coupled quantum device such as a quantum point contact or single electron transistor, making dispersive sensing particularly interesting for gate-defined graphene quantum dots.
