Nilsson Johan, Castro Neto A H
Department of Physics, Boston University, Boston, Massachusetts 02215, USA.
Phys Rev Lett. 2007 Mar 23;98(12):126801. doi: 10.1103/PhysRevLett.98.126801. Epub 2007 Mar 20.
We study the problem of impurities and midgap states in a biased graphene bilayer. We show that the properties of the bound states, such as localization lengths and binding energies, can be controlled externally by an electric field effect. Moreover, the band gap is renormalized and impurity bands are created at finite impurity concentrations. Using the coherent potential approximation, we calculate the electronic density of states and its dependence on the applied bias voltage.
我们研究了偏置双层石墨烯中的杂质和带隙中间态问题。我们表明，束缚态的性质，如局域长度和结合能，可以通过电场效应从外部进行控制。此外，带隙会发生重整化，并且在有限的杂质浓度下会产生杂质带。我们使用相干势近似方法，计算了态密度及其与所施加偏置电压的依赖关系。
