Quantum Hall Effects in Silicene
Quantum Hall Effects in Silicene
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DOI：
10.1143/jpsj.81.064705
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发表时间：
2012-06-01
影响因子：
1.7
通讯作者：
Ezawa, Motohiko
中科院分区：
文献类型：
--
作者：
Ezawa, Motohiko
本文研究了在平行于磁场的电场E-z作用下硅烯的量子霍尔效应。硅烯是形成二维蜂窝晶格的硅原子单层，并且与石墨烯共享几乎所有显着的特性。一个新的特点是它的屈曲结构，由于它的能带结构可以通过改变E-z外部控制。硅烯的低能物理学由质量狄拉克费米子描述，其中质量是E-z的函数，并且在临界场E-cr处变为零。我们表明，有没有零能量状态，由于狄拉克质量项，除了在临界电场E-cr。此外，它表明，4重简并零能态是完全解决，即使不考虑库仑相互作用。这些特征与石墨烯中的特征形成了高度对比，表明硅烯具有更丰富的结构。其突出特点是通过外加电场可以控制谷简并度。作为E-z的函数，霍尔平台出现在填充因子v = 0，+/-l; +/- 2; +/- 3，.除了发生水平交叉的点之外。
We investigate quantum Hall effects in silicene by applying electric field E-z parallel to magnetic field. Silicene is a monolayer of silicon atoms forming a two-dimensional honeycomb lattice, and shares almost every remarkable property with graphene. A new feature is its buckled structure, due to which the band structure can be controlled externally by changing E-z. The low energy physics of silicene is described by massive Dirac fermions, where the mass is a function of E-z and becomes zero at the critical field E-cr. We show that there are no zero energy states due to the Dirac mass term except at the critical electric field E-cr. Furthermore it is shown that the 4-fold degenerate zero-energy states are completely resolved even without considering Coulomb interactions. These features are highly contrasted with those in graphene, demonstrating that silicene has a richer structure. The prominent feature is that, by applying the electric field, we can control the valley degeneracy. As a function of E-z, Hall plateaux appear at the filling factors v = 0, +/- 1; +/- 2; +/- 3,... except for the points where level crossings occur.