石墨烯2种电导率模型的比较与分析  

Comparison and analysis on two conductivity models of graphene

作　　者：陈秀艳[1] 石钠月 CHEN Xiuyan;SHI Nayue(College of Physical Science and Technology, Shenyang Normal University, Shenyang 110034, China)

机构地区：[1]沈阳师范大学物理科学与技术学院,沈阳110034

出　　处：《沈阳师范大学学报（自然科学版）》2022年第1期24-29,共6页Journal of Shenyang Normal University:Natural Science Edition

基　　金：国家自然科学基金资助项目(61603265)。

摘　　要：基于2种不同的描述石墨烯电导率的公式(Kubo公式和Drude公式),对于微波波段石墨烯的电导率、介电常数及折射率进行了计算,并将得到的结果进行比较与分析。结果表明,2种微波波段公式得到的石墨烯电导率相差无几,介电常数虚部完全相同,但实部有着明显的差异。Kubo公式计算出来的介电常数实部随着频率的增加趋近于Drude公式计算出来的结果,这是由于Kubo公式与Drude公式之间所差的带间跃迁的表达式及过于简化的Drude公式造成的。基于2种公式计算出的石墨烯折射率的变化趋势相同,并没有受到介电常数结果的影响。因此,在石墨烯的计算与应用时,在微波波段只考虑电导率及折射率的情况下,用2种公式都可以,Drude公式更便于计算,但需要应用介电常数时,Kubo公式更加合适,更能确保得到的介电常数与实际相接近。Based on Kubo formula and Drude formula,the conductivity,dielectric constant and refractive index of graphene in microwave band are calculated,and the results are compared and analyzed.The results show that the conductivity of graphene obtained by the two formulas in microwave band is almost the same,but the real part of dielectric constant is obviously different,and the imaginary part is exactly the same.The real part of the dielectric constant calculated by Kubo formula is close to the result calculated by Drude formula with the increase of frequency.This difference is due to the expression of the inter band transition between Kubo formula and Drude formula and the oversimplification of Drude formula.The refractive index of graphene calculated by the two formulas is the same,and is not affected by the dielectric constant.Therefore,in the calculation and application of graphene,both formulas can be used when only conductivity and refractive index are considered in the microwave band.Drude formula is more convenient for calculation,but Kubo formula is more appropriate when dielectric constant needs to be applied,which can better ensure that the obtained dielectric constant is close to the reality.

关 键 词：石墨烯电导率 介电常数 折射率 Kubo公式 Drude近似公式 

分 类 号：O487[理学—固体物理]