Resonant Scattering by Magnetic Impurities as a Model for Spin Relaxation in Bilayer Graphene.
Resonant Scattering by Magnetic Impurities as a Model for Spin Relaxation in Bilayer Graphene.
复制标题
磁性杂质的共振散射作为双层石墨烯自旋弛豫的模型。
DOI：
10.1103/physrevlett.115.196601
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发表时间：
2015
影响因子：
8.6
通讯作者：
J. Fabian
中科院分区：
文献类型：
--
作者：
D. Kochan;Susanne Irmer;M. Gmitra;J. Fabian
我们建议，所观察到的自旋弛豫双层石墨烯是由于磁性杂质的共振散射。我们分析了共振散射模型，由于吸附原子上的二聚体和非二聚体网站，发现只有前者给在电荷中性点的窄共振。与单层石墨烯相反，石墨烯双层中测得的自旋弛豫速率随着载流子密度的增加而增加。虽然人们普遍认为，不同的机制必须在两种结构中发挥作用，我们的模型解释了这种行为，而自然的不同的加宽尺度相同的基础共振过程。不仅我们的结果-使用强大的和第一原理的启发参数-同意与实验，他们还预测实验可测试的急剧下降的自旋弛豫率在高载流子密度。
We propose that the observed spin relaxation in bilayer graphene is due to resonant scattering by magnetic impurities. We analyze a resonant scattering model due to adatoms on both dimer and nondimer sites, finding that only the former give narrow resonances at the charge neutrality point. Opposite to single-layer graphene, the measured spin-relaxation rate in the graphene bilayer increases with carrier density. Although it has been commonly argued that a different mechanism must be at play for the two structures, our model explains this behavior rather naturally in terms of different broadening scales for the same underlying resonant processes. Not only do our results-using robust and first-principles inspired parameters-agree with experiment, they also predict an experimentally testable sharp decrease of the spin-relaxation rate at high carrier densities.