论文标题
流体动力电子的当前噪声
Current Noise of Hydrodynamic Electrons
论文作者
论文摘要
有限温度下的电阻会产生称为Johnson-Nyquist噪声的电流的白噪声波动。测量此噪声的幅度提供了一种强大的主要温度测量技术来进入电子温度。但是，在实际情况下，需要概括约翰逊 - 尼奎斯特定理以处理空间不均匀的温度曲线。最近的工作为遵守Wiedemann-Franz定律的欧姆设备提供了这样的概括，但是有必要为流体动力电子系统提供类似的概括，因为流体力学电子为Johnson噪声温度测定提供了异常的敏感性，但他们不承认当地的电导率，也不遵守Wiedemann-Franz法律。在这里，我们通过考虑矩形几何形状的流体动力环境中的低频约翰逊噪声来满足这种需求。与欧姆环境不同，我们发现约翰逊噪声由于非本地粘性梯度而依赖于几何形状。尽管如此，与使用欧姆结果的天然相比，忽略几何校正仅导致最多40％的误差。
A resistor at finite temperature produces white noise fluctuations of the current called Johnson-Nyquist noise. Measuring the amplitude of this noise provides a powerful primary thermometry technique to access the electron temperature. In practical situations, however, one needs to generalize the Johnson-Nyquist theorem to handle spatially inhomogeneous temperature profiles. Recent work provided such a generalization for ohmic devices obeying the Wiedemann-Franz law, but there is a need to provide a similar generalization for hydrodynamic electron systems, since hydrodynamic electrons provide unusual sensitivity for Johnson noise thermometry but they do not admit a local conductivity nor obey the Wiedemann-Franz law. Here we address this need by considering low-frequency Johnson noise in the hydrodynamic setting for a rectangular geometry. Unlike in the ohmic setting, we find that the Johnson noise is geometry-dependent due to non-local viscous gradients. Nonetheless, ignoring the geometric correction only leads to an error of at most 40% as compared to naively using the ohmic result.
