Magnetic-field-induced charge redistribution in disordered graphene double quantum dots
Magnetic-field-induced charge redistribution in disordered graphene double quantum dots
复制标题
DOI：
10.1103/physrevb.92.155408
复制
发表时间：
2015-05
影响因子：
3.7
通讯作者：
K. Chiu;M. Connolly;A. Cresti;J. Griffiths;G. Jones;C. Smith
中科院分区：
文献类型：
--
作者：
K. Chiu;M. Connolly;A. Cresti;J. Griffiths;G. Jones;C. Smith
我们研究了大石墨烯双量子点在背景无序势和磁场影响下的输运特性。在低温下，研究了高达 10 特斯拉的充电稳定性图作为 B 场函数的演变。我们的结果表明，在高磁场下，量子点的充电能量降低，因此量子点的尺寸增大。我们使用紧束缚模型对结果进行了解释，该模型描述了无序石墨烯量子点中通过朗道能级和边缘态形成的电荷重新分布。我们的模型表明，在高 B 场下，分隔点中不同电子/空穴坑的隧道势垒变得透明，导致实验观察到的电荷离域和充电能量降低。
We have studied the transport properties of a large graphene double quantum dot under the influence of background disorder potential and magnetic field. At low temperatures, the evolution of the charge-stability diagram as a function of B-field is investigated up to 10 Tesla. Our results indicate that the charging energy of quantum dot is reduced, and hence the size of the dot increases, at high magnetic field. We provide an explanation of our results using a tight-binding model, which describes the charge redistribution in a disordered graphene quantum dot via the formation of Landau levels and edge states. Our model suggests that the tunnel barriers separating different electron/hole puddles in a dot become transparent at high B-fields, resulting in the charge delocalization and reduced charging energy observed experimentally.