Abstract

We study the energy spectrum and persistent current of charge carriers confined in a graphene quantum ring geometry of radius R and width w subject to a magnetic flux. We consider the case where the crystal symmetry is locally modified through dislocations created by replacing the original carbon hexagon by a pentagon, square, heptagon or octagon. To model this type of defect, we include appropriate boundary conditions for the angular coordinate. The electrons are then confined to a finite width strip in the radial direction by setting an infinite mass boundary conditions at the edges of the strip. The solutions are expressed in terms of Hankel functions and their asymptotic behavior allows to derive quantized energy levels in the presence of an energy gap. We also investigate the persistent currents that appear in the quantum ring in the presence of a quantum flux at the center of the ring and how wedge disclination influences different quantum transport quantities.

Graphic Abstract

中文翻译：

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楔形位错的石墨烯量子环的电子性质

摘要

我们研究了限制在半径为R和宽度为w的石墨烯量子环几何结构中的电荷载流子的能谱和持久电流受到磁通量的影响。我们考虑这样的情况，其中晶体对称性是通过以五边形，正方形，七边形或八边形代替原始碳六边形而产生的位错来局部修改的。为了对这种类型的缺陷建模，我们为角坐标包括了适当的边界条件。然后，通过在电子束的边缘设置无限的质量边界条件，将电子限制在径向上的有限宽度的电子束中。这些解以汉克尔函数表示，它们的渐近行为允许在存在能隙的情况下得出量化的能级。我们还研究了在环中心存在量子通量的情况下出现在量子环中的持久电流，以及楔形位错如何影响不同的量子传输量。

图形摘要