Single-Electron Double Quantum Dots in Bilayer Graphene
Single-Electron Double Quantum Dots in Bilayer Graphene
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DOI：
10.1021/acs.nanolett.9b05295
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发表时间：
2020-03-11
期刊：
影响因子：
10.8
通讯作者：
Stampfer, Christoph
中科院分区：
文献类型：
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作者：
Banszerus, Luca;Moeller, Samuel;Stampfer, Christoph
我们目前的运输测量通过静电定义的双层石墨烯双量子点在单电子制度。在一个背栅、两个分裂栅和两个指状栅的帮助下，我们能够独立地控制两个栅定义的量子点上的载流子数量在0到5之间。该器件的高可调谐性满足了使这种器件成为自旋量子比特的合适构建块的要求。在单电子制度，我们确定点间隧道速率的顺序为2 GHz。点间隧道耦合和电容性点间耦合都随着点的占据而增加，导致向单个量子点的转变。有限偏置磁谱测量允许解决的激发态光谱的第一个电子在双量子点，并在协议与自旋和谷守恒点间隧穿过程。
We present transport measurements through an electrostatically defined bilayer graphene double quantum dot in the single-electron regime. With the help of a back gate, two split gates, and two finger gates, we are able to control the number of charge carriers on two gate-defined quantum dots independently between zero and five. The high tunability of the device meets requirements to make such a device a suitable building block for spin-qubits. In the single-electron regime, we determine interdot tunnel rates on the order of 2 GHz. Both, the interdot tunnel coupling as well as the capacitive interdot coupling increase with dot occupation, leading to the transition to a single quantum dot. Finite bias magneto-spectroscopy measurements allow to resolve the excited-state spectra of the first electrons in the double quantum dot and are in agreement with spin and valley conserving interdot tunneling processes.