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arXiv 2211.01366cond-mat.mes-hallcond-mat.str-el
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流体动力学电子的电流噪声

Current Noise of Hydrodynamic Electrons

Aaron Hui, Brian Skinner

AI总结:

本文研究矩形几何中流体动力学电子的低频Johnson噪声,发现其因非局域粘性梯度而具有几何依赖性,并证明忽略几何修正相对欧姆结果最多产生40%误差。

摘要:

有限温度下的电阻器会产生称为Johnson-Nyquist噪声的电流白噪声涨落。测量该噪声的幅度提供了一种强大的初级测温技术,用于获取电子温度。然而,在实际情况下,需要推广Johnson-Nyquist定理以处理空间非均匀的温度分布。近期研究为服从Wiedemann-Franz定律的欧姆器件提供了这样的推广,但仍需为流体动力学电子系统提供类似的推广,因为流体动力学电子为Johnson噪声测温提供了非凡的灵敏度,但它们既不具有局域电导率,也不服从Wiedemann-Franz定律。本文通过考虑矩形几何中流体动力学背景下的低频Johnson噪声来满足这一需求。与欧姆情形不同,我们发现由于非局域粘性梯度,Johnson噪声依赖于几何形状。尽管如此,与直接使用欧姆结果的朴素做法相比,忽略几何修正最多只会导致40%的误差。

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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