JARA-FIT and II. Institute of Physics B, RWTH Aachen University, 52074 Aachen, Germany.
Nano Lett. 2011 Sep 14;11(9):3581-6. doi: 10.1021/nl201295s. Epub 2011 Aug 19.
We report tunneling spectroscopy experiments on a bilayer graphene double quantum dot device that can be tuned by all-graphene lateral gates. The diameter of the two quantum dots are around 50 nm and the constrictions acting as tunneling barriers are 30 nm in width. The double quantum dot features additional energies on the order of 20 meV. Charge stability diagrams allow us to study the tunable interdot coupling energy as well as the spectrum of the electronic excited states on a number of individual triple points over a large energy range. The obtained constant level spacing of 1.75 meV over a wide energy range is in good agreement with the expected single-particle energy spacing in bilayer graphene quantum dots. Finally, we investigate the evolution of the electronic excited states in a parallel magnetic field.
我们报告了在双层石墨烯双量子点器件上进行的隧道谱实验，该器件可以通过全石墨烯横向门进行调谐。两个量子点的直径约为 50nm，作为隧道势垒的限制宽度为 30nm。双量子点具有额外的约 20meV 的能量。电荷稳定图允许我们在很大的能量范围内研究可调谐的点间耦合能量以及电子激发态的谱在许多单个三重点上。在很宽的能量范围内获得的 1.75meV 的恒定能级间距与双层石墨烯量子点中预期的单粒子能隙很好地吻合。最后，我们研究了在平行磁场中电子激发态的演化。
