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论文专利

郑以松课题研究论文在SCIENTIFIC REPORTS上发表

发布时间:2016年 04月 27日 07时 58分 编辑: 点击量:428

Conductivity tensor of graphene dominated by spin-orbit coupling scatterers: A comparison between the results from Kubo and Boltzmann transport theories




Authors:

Zhe Liu, Liwei Jiang & YisongZheng


Abstract:

The diagonal and Hall conductivities of graphene arising from the spin-orbit coupling impurity scattering are theoretically studied. Based on the continuous model, i.e. the massless Dirac equation, we derive analytical expressions of the conductivity tensor from both the Kubo and Boltzmann transport theories. By performing numerical calculations, we find that the Kubo quantum transport result of the diagonal conductivity within the self-consistent Born approximation exhibits an insulating gap around the Dirac point. And in this gap a well-defined quantized spin Hall plateau occurs. This indicates the realization of the quantum spin Hall state of graphene driven by the spin-orbit coupling impurities. In contrast, the semi-classical Boltzmann theory fails to predict such a topological insulating phase. The Boltzmann diagonal conductivity is nonzero even in the insulating gap, in which the Boltzmann spin Hall conductivity does not exhibit any quantized plateau.


Published in Journal of SCIENTIFIC REPORTS(IF=5.578) on 31 Mar 2016 


Resource:

http://www.nature.com/articles/srep23762