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arXiv 1807.09130cond-mat.mes-hallcond-mat.mtrl-sci
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化学势对石墨烯红外和微波反射率的影响

Impact of chemical potential on the reflectance of graphene in the infrared and microwave domains

G. L. Klimchitskaya, V. M. Mostepanenko, V. M. Petrov

摘要:

在狄拉克模型的框架下,考虑到石墨烯的实际性质,如非零的化学势和带隙,在任何温度下,石墨烯的反射率进行了研究。为此目的,已经使用了石墨烯片上的电磁波的精确反射系数,该反射系数通过极化张量并且最终通过石墨烯的电导率来表示。石墨烯的反射率被计算为在不同温度和带隙参数值下的频率和化学势的函数。在红外区域,石墨烯的电导率虚部消失的点处,反射率达到最小值。对于带间隙的石墨烯,在电导率的虚部发散的点处达到等于1的最大反射率。计算结果表明,带隙和化学势之间的一个有趣的相互作用,在它们的反射率的组合效果。具体地,存在宽的频率间隔,其中石墨烯的反射率随着化学势的增加和带隙的减小而增加。数值计算发现,在其适用范围内的解析渐近表达式是在很好的协议。列出了几个技术领域,其中所获得的结果可以使用。

英文摘要:

The reflectance of graphene is investigated in the framework of the Dirac model with account of its realistic properties, such as nonzero chemical potential and band gap, at any temperature. For this purpose, the exact reflection coefficients of the electromagnetic waves on a graphene sheet expressed via the polarization tensor and ultimately via the electrical conductivity of graphene have been used. The reflectance of graphene is computed as a function of frequency and chemical potential at different temperatures and values of the band-gap parameter. The minimum values of the reflectance are found which are reached in the infrared domain at the points of vanishing imaginary part of the conductivity of graphene. For a gapped graphene, the maximum reflectance equal to unity is reached at the points where the imaginary part of conductivity diverges. The computational results demonstrate an interesting interplay between the band gap and chemical potential in their combined effect on the reflectance. Specifically, there are wide frequency intervals where the reflectance of graphene increases with increasing chemical potential and decreasing band gap. The numerical computations are found to be in good agreement with the analytic asymptotic expressions in the regions of their applicability. Several technological areas, where the obtained results could be used, are listed.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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