Disorder-enabled hydrodynamics of charge and heat transport in monolayer graphene
Disorder-enabled hydrodynamics of charge and heat transport in monolayer graphene
复制标题
单层石墨烯中电荷和热传输的无序流体动力学
作者：
M. Zarenia;A. Principi;G. Vignale
人们普遍认为电子系统中的流体动力学行为与极其干净的样品有关，因此电子-电子碰撞占主导地位并且总动量守恒。与此相反，我们表明，在单层石墨烯中，无序的存在对于实现电荷中性点附近的非常规流体动力学状态至关重要，其特征是维德曼-弗朗兹比的大幅增强。尽管随着紊乱的减少，增强作用变得更加明显，但观察到效果的可能性很大程度上取决于紊乱的存在。我们计算了最大外在载流子密度 nc ，低于该密度时效果变得明显，并表明 nc 在零无序极限下消失。对于 n > nc，我们预测 Wiedemann-Franz 比率实际上随着无序度的减少而降低。我们通过呈现一个透明的物理过程图来完成我们的分析，这些物理过程负责从传统流体动力学到无序流体动力学的交叉。最近对单层石墨烯的实验进行了讨论，并显示与该图一致。
Hydrodynamic behavior in electronic systems is commonly accepted to be associated with extremely clean samples such that electron–electron collisions dominate and total momentum is conserved. Contrary to this, we show that in monolayer graphene the presence of disorder is essential to enable an unconventional hydrodynamic regime which exists near the charge neutrality point and is characterized by a large enhancement of the Wiedemann–Franz ratio. Although the enhancement becomes more pronounced with decreasing disorder, the very possibility of observing the effect depends crucially on the presence of disorder. We calculate the maximum extrinsic carrier density nc below which the effect becomes manifest, and show that nc vanishes in the limit of zero disorder. For n > nc we predict that the Wiedemann–Franz ratio actually decreases with decreasing disorder. We complete our analysis by presenting a transparent picture of the physical processes that are responsible for the crossover from conventional to disorder-enabled hydrodynamics. Recent experiments on monolayer graphene are discussed and shown to be consistent with this picture.
影响因子：
3.7
作者：
Gornyi, I. V.;Kachorovskii, V. Yu.;Mirlin, A. D.
通讯作者：
Mirlin, A. D.