Dirac gap-induced graphene quantum dot in an electrostatic potential
Dirac gap-induced graphene quantum dot in an electrostatic potential
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DOI：
10.1103/physrevb.83.165427
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发表时间：
2011-04-19
影响因子：
3.7
通讯作者：
Nori, Franco
中科院分区：
文献类型：
--
作者：
Giavaras, G.;Nori, Franco
石墨烯片中的空间调制狄拉克隙导致电荷约束，从而使石墨烯量子点在不施加外部电场和磁场的情况下形成[G]。Giavaras和F. Nori，苹果。理论物理。科学通报，2012,(3)[j]。这是可以实现的，只要狄拉克间隙有一个局部最小值，在这个最小值中状态变得局域化。本文通过求解狄拉克方程，在连续介质极限下研究了这种间隙感应点的物理性质。结果表明，间隙诱导的约束态与静电量子阱势引入的态是耦合的。因此，由此产生的杂化态所在的区域可以根据势强度进行调谐，这种效应涉及克莱因隧道效应。所提出的量子点可用于探测石墨烯中的准相对论效应，而诱导的受限态可用于石墨烯基纳米结构。
A spatially modulated Dirac gap in a graphene sheet leads to charge confinement, thus enabling a graphene quantum dot to be formed without the application of external electric and magnetic fields [G. Giavaras and F. Nori, Appl. Phys. Lett. 97, 243106 (2010)]. This can be achieved provided the Dirac gap has a local minimum in which the states become localized. In this work, the physics of such a gap-induced dot is investigated in the continuum limit by solving the Dirac equation. It is shown that gap-induced confined states couple to the states introduced by an electrostatic quantum well potential. Hence the region in which the resulting hybridized states are localized can be tuned with the potential strength, an effect which involves Klein tunneling. The proposed quantum dot may be used to probe quasirelativistic effects in graphene, while the induced confined states may be useful for graphene-based nanostructures.