Conductivity of suspended graphene at the Dirac point
Conductivity of suspended graphene at the Dirac point
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DOI：
10.1103/physrevb.86.165413
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发表时间：
2012-10-09
影响因子：
3.7
通讯作者：
Mirlin, A. D.
中科院分区：
文献类型：
--
作者：
Gornyi, I. V.;Kachorovskii, V. Yu.;Mirlin, A. D.
我们研究了纯净悬浮石墨烯在狄拉克点的输运性质。在没有电子-电子相互作用的情况下，电阻率的主要贡献来自与弯曲（面外变形）声子的相互作用。我们发现声子限制电导率随温度的变化而变化，其中。是描述由于与平面内声子的非谐波耦合而导致的弯曲声子相关函数的重整化的临界指数（根据数值研究近似等于0.7）。电子-电子相互作用诱导了额外的散射机制，并通过屏蔽变形势来影响电子-声子散射。我们证明了这两种相互作用的综合效应导致电导率可以表示为两个温度相关的无量纲常数G[T]和G(e)[T]的无量纲函数，它们分别表征了电子-声子和电子-电子相互作用的强度。我们还讨论了远离狄拉克点的电导率行为以及杂质势的作用，并将我们的预测与现有的实验数据进行了比较。
We study transport properties of clean suspended graphene at the Dirac point. In the absence of the electron-electron interaction, the main contribution to resistivity comes from interaction with flexural (out-of-plane deformation) phonons. We find that the phonon-limited conductivity scales with the temperature as T-n, where. is the critical exponent (equal to approximate to 0.7 according to numerical studies) describing renormalization of the flexural phonon correlation functions due to anharmonic coupling with the in-plane phonons. The electron-electron interaction induces an additional scattering mechanism and also affects the electron-phonon scattering by screening the deformation potential. We demonstrate that the combined effect of both interactions results in a conductivity that can be expressed as a dimensionless function of two temperature-dependent dimensionless constants, G[T] and G(e)[T], which characterize the strength of electron-phonon and electron-electron interactions, respectively. We also discuss the behavior of conductivity away from the Dirac point as well as the role of the impurity potential and compare our predictions with available experimental data.