LPS, Université Paris-Sud, CNRS, UMR 8502, F-91405 Orsay Cedex, France.
Phys Rev Lett. 2010 Mar 26;104(12):126801. doi: 10.1103/PhysRevLett.104.126801.
Transport and elastic scattering times, tau{tr} and tau{e}, are experimentally determined from the carrier density dependence of the magnetoconductance of monolayer and bilayer graphene. Both times and their dependences on carrier density are found to be very different in the monolayer and the bilayer. However, their ratio tau{tr}/tau{e} is found to be close to 1.8 in the two systems and nearly independent of the carrier density. These measurements give insight on the nature (neutral or charged) and range of the scatterers. Comparison with theoretical predictions suggests that the main scattering mechanism in our samples is due to strong (resonant) scatterers of a range shorter than the Fermi wavelength, likely candidates being vacancies, voids, adatoms or short-range ripples.
载流子密度对单层和双层石墨烯磁导率的依赖关系实验确定了输运和弹性散射时间τtr 和 τe。在单层和双层中，这两个时间及其对载流子密度的依赖性有很大的不同。然而，在这两个系统中，τtr/τe 的比值接近 1.8，并且几乎与载流子密度无关。这些测量提供了有关散射体性质（中性或带电）和范围的信息。与理论预测的比较表明，在我们的样品中，主要的散射机制是由于短于费米波长的强（共振）散射体，可能的候选者是空位、空隙、 adatoms 或短程波纹。
