论文标题
双层石墨烯中电导率温度崩溃的起源
Origin of the Temperature Collapse of the Electric Conductivity in Bilayer Graphene
论文作者
论文摘要
最近的实验报道了悬浮双层石墨烯的电导率中显性电子孔散射的证据，靠近电荷中性。根据这些实验，电导率的图与$ 12 \ rm {k} \ rm {k} \ sillsim t \ lyseSim t \ lyssim 40 \ rm {k rm {k rm {k rm {k} $在单个曲线上倒在$ t $独立于$ t $的范围内获得的不同温度的函数（化学势缩放为温度）。在最近的理论中，该观察结果被认为是主要的亚基散射过程不是电子障碍，而是电子 - phonon。在这里，我们证明可以在不调用电子播种的情况下解释数据上数据的崩溃，但是假设悬浮的双层石墨烯并不是真正的无间隙系统。凭借$ \ sim 5 $ MEV的差距，我们的理论与观测到的电导率在全报告的温度范围内产生了极好的一致性。这些结果基于电导率的流体动力学理论，因此作为实验分析和多频道系统中带隙的估计的坚实基础。
Recent experiments have reported evidence of dominant electron-hole scattering in the electric conductivity of suspended bilayer graphene near charge neutrality. According to these experiments, plots of the electric conductivity as a function of $μ/k_BT$ (chemical potential scaled with temperature) obtained for different temperatures in the range of $12\rm{K}\lesssim T \lesssim 40\rm{K}$ collapse on a single curve independent of $T$. In a recent theory, this observation has been taken as an indication that the main sub-dominant scattering process is not electron-impurity but electron-phonon. Here we demonstrate that the collapse of the data on a single curve can be explained without invoking electron-phonon scattering, but assuming that the suspended bilayer graphene is not a truly gapless system. With a gap of $\sim 5$ meV, our theory produces excellent agreement with the observed conductivity over the full reported range of temperatures. These results are based on the hydrodynamic theory of conductivity, which thus emerges as a solid foundation for the analysis of experiments and the estimation of the band-gap in multiband systems.
