On the universal ac optical background in graphene
On the universal ac optical background in graphene
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DOI：
10.1088/1367-2630/11/9/095013
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发表时间：
2009-09-30
影响因子：
3.3
通讯作者：
Carbotte, J. P.
中科院分区：
文献类型：
--
作者：
Gusynin, V. P.;Sharapov, S. G.;Carbotte, J. P.
最新的实验证实了理论上预期的石墨烯交流电导率的普适值pie（2/）2 h，并揭示了准粒子动力学与理想化石墨烯中狄拉克费米子预测的偏离。我们提出了石墨烯的交流电导率的解析表达式，使人们能够研究它是如何受到相互作用，温度，外部磁场和准粒子谱中的间隙的开口的影响。我们表明，石墨烯的交流电导率不一定给出冯克利青常数h/e（2）的计量学准确值，因为它是由电子-声子相互作用耗尽。在弱磁场中，交流电导率在普适值附近振荡，Drude峰演变为回旋频率处的峰。
Latest experiments have confirmed the theoretically expected universal value pi e(2/)2h of the ac conductivity of graphene and have revealed departures of the quasi-particle dynamics from predictions for the Dirac fermions in idealized graphene. We present analytical expressions for the ac conductivity in graphene that allow one to study how it is affected by interactions, temperature, external magnetic field and the opening of a gap in the quasi-particle spectrum. We show that the ac conductivity of graphene does not necessarily give a metrologically accurate value of the von Klitzing constant h/e(2), because it is depleted by the electron-phonon interaction. In a weak magnetic field, the ac conductivity oscillates around the universal value and the Drude peak evolves into a peak at the cyclotron frequency.