标题： 作为探测石墨烯基异质结中安德烈夫反射的散粒噪声 显示英文标题

标题： Shot noise as a probe for Andreev reflection in graphene-based heterojunctions

摘要： 由于电荷传输的离散性，会产生散粒噪声，并直接揭示控制介观导体中电流流动的微观传输机制。 在本工作中，我们证明量子散粒噪声为安德列夫反射提供了一种直接且稳健的特征指纹，能够在石墨烯-超导体、石墨烯-超导体-石墨烯以及超导体-石墨烯-超导体结中区分反向和镜面过程。 在石墨烯-超导体界面，通过玻利乌波-德热纳形式下的全波函数匹配得到的精确反射振幅捕捉了反向和镜面区域。 相关的法诺因子表现出不同的费米能级依赖特征，其中反向安德列夫反射抑制而镜面安德列夫反射增强散粒噪声。 扩展到石墨烯-超导体-石墨烯和超导体-石墨烯-超导体配置，揭示了在存在多个界面、相干准粒子干涉和超导相位变化的情况下，传输谱及相应的噪声轮廓是如何被修改的。 我们的研究结果确立了散粒噪声光谱学作为一种强大且实验可行的探测方法，用于区分基于石墨烯的量子器件中的安德列夫反射类型，提供了超越传统电导测量的补充见解。 显示英文摘要

摘要： Shot noise emerges due to the discrete nature of charge transport and provides direct access to the underlying microscopic transport mechanisms governing current flow in mesoscopic conductors. In this work, we demonstrate that quantum shot noise offers a direct and robust fingerprint of Andreev reflection, distinguishing between retro and specular processes in graphene-superconductor, graphene-superconductor-graphene, and superconductor-graphene-superconductor junctions. At the graphene-superconductor interface, exact reflection amplitudes obtained from full wavefunction matching within the Bogoliubov-de Gennes formalism capture retro and specular regimes. The associated Fano factor exhibits distinct Fermi-level-dependent signatures, with retro Andreev reflection suppressing and specular Andreev reflection enhancing the shot noise. Extensions to graphene-superconductor-graphene and superconductor-graphene-superconductor configurations reveal how the transmission spectrum and, consequently, the noise profile are modified in the presence of multiple interfaces, coherent quasiparticle interference, and superconducting phase variations. Our findings establish shot noise spectroscopy as a potent and experimentally viable probe for differentiating Andreev reflection types in graphene-based quantum devices, providing complementary insights beyond conventional conductance measurements.