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arXiv 0904.3182cond-mat.mes-hall
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磁场中石墨烯环的Aharonov-Bohm效应和谷分裂

Graphene Rings in Magnetic Fields: Aharonov-Bohm Effect and Valley Splitting

J. Wurm, M. Wimmer, H. U. Baranger, K. Richter

摘要:

基于紧束缚模型,通过数值计算研究了介观石墨烯环在垂直磁场作用下的电导。首先,我们考虑这种环的磁导,并观察Aharonov-Bohm效应。我们研究了不同制度的磁通量的量子霍尔制度,其中Aharonov-Bohm振荡被抑制。清洁(弹道)和无序(扩散)环的结果。第二,我们研究了弱耦合到引线的光滑质量边界环。我们发现,在封闭的石墨烯环的本征态的谷简并可以通过一个小的磁通量提升,这种提升可以观察到系统的输运性质。

英文摘要:

We study the conductance of mesoscopic graphene rings in the presence of a perpendicular magnetic field by means of numerical calculations based on a tight-binding model. First, we consider the magnetoconductance of such rings and observe the Aharonov-Bohm effect. We investigate different regimes of the magnetic flux up to the quantum Hall regime, where the Aharonov-Bohm oscillations are suppressed. Results for both clean (ballistic) and disordered (diffusive) rings are presented. Second, we study rings with smooth mass boundary that are weakly coupled to leads. We show that the valley degeneracy of the eigenstates in closed graphene rings can be lifted by a small magnetic flux, and that this lifting can be observed in the transport properties of the system.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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