We perform simulations, by means of an envelope-function-based approach, of shot noise in disordered monolayer graphene devices, as a function of the gate bias voltage. In order to approach the experimental conditions, large graphene samples with characteristic sizes of the order of hundreds of nanometers or microns have been considered. We investigate different device geometries, including back-gated graphene samples with different aspect ratios and a graphene constriction biased by two side gates. We compare our results with available experimental data that were collected by a few authors in an attempt to validate an interesting prediction made by Tworzydło et al. [Phys. Rev. Lett. 96, 246802 (2006)] on the shot noise dependence on carrier density in samples with a large aspect ratio. On the basis of the comparison of our results with the experimental data, we conclude that the effect predicted by Tworzydło et al. (resulting from the distribution of the transmission eigenvalues associated with propagation via evanescent modes) has not been observed yet. Finally, we provide some guidelines for the design of experiments aimed at the verification of such an effect.

中文翻译：

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基于包络函数的散粒噪声对无序石墨烯样品中栅极电压依赖性的分析

我们通过基于包络函数的方法对无序单层石墨烯器件中的散粒噪声进行模拟，作为栅极偏置电压的函数。为了接近实验条件，已经考虑了具有数百纳米或微米数量级的特征尺寸的大型石墨烯样品。我们研究了不同的器件几何形状，包括具有不同纵横比的背栅石墨烯样品和由两个侧栅偏置的石墨烯收缩。我们将我们的结果与一些作者收集的可用实验数据进行比较，试图验证 Tworzydło等人做出的有趣预测。[物理。牧师莱特。 96, 246802 (2006)] 关于散粒噪声对大纵横比样品中载流子密度的依赖性。根据我们的结果与实验数据的比较，我们得出结论，Tworzydło等人预测的效果。（由于与通过渐逝模式传播相关的传输特征值的分布）尚未观察到。最后，我们为旨在验证这种效果的实验设计提供了一些指导。