Lumbroso Ofir Shein, Simine Lena, Nitzan Abraham, Segal Dvira, Tal Oren
Department of Chemical and Biological Physics, Weizmann Institute of Science, Rehovot, Israel.
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada.
Nature. 2018 Oct;562(7726):240-244. doi: 10.1038/s41586-018-0592-2. Epub 2018 Oct 10.
Since the discovery a century ago of electronic thermal noise and shot noise, these forms of fundamental noise have had an enormous impact on science and technology research and applications. They can be used to probe quantum effects and thermodynamic quantities, but they are also regarded as undesirable in electronic devices because they obscure the target signal. Electronic thermal noise is generated at equilibrium at finite (non-zero) temperature, whereas electronic shot noise is a non-equilibrium current noise that is generated by partial transmission and reflection (partition) of the incoming electrons. Until now, shot noise has been stimulated by a voltage, either applied directly or activated by radiation. Here we report measurements of a fundamental electronic noise that is generated by temperature differences across nanoscale conductors, which we term 'delta-T noise'. We experimentally demonstrate this noise in atomic and molecular junctions, and analyse it theoretically using the Landauer formalism. Our findings show that delta-T noise is distinct from thermal noise and voltage-activated shot noise. Like thermal noise, it has a purely thermal origin, but delta-T noise is generated only out of equilibrium. Delta-T noise and standard shot noise have the same partition origin, but are activated by different stimuli. We infer that delta-T noise in combination with thermal noise can be used to detect temperature differences across nanoscale conductors without the need to fabricate sophisticated local probes. Thus it can greatly facilitate the study of heat transport at the nanoscale. In the context of modern electronics, temperature differences are often generated unintentionally across electronic components. Taking into account the contribution of delta-T noise in these cases is likely to be essential for the design of efficient nanoscale electronics at the quantum limit.
自一个世纪前发现电子热噪声和散粒噪声以来，这些基本噪声形式对科学技术研究及应用产生了巨大影响。它们可用于探测量子效应和热力学量，但在电子设备中也被视为不良因素，因为它们会掩盖目标信号。电子热噪声是在有限（非零）温度的平衡状态下产生的，而电子散粒噪声是一种非平衡电流噪声，由入射电子的部分透射和反射（分配）产生。到目前为止，散粒噪声一直是由电压激发的，该电压要么直接施加，要么由辐射激活。在此，我们报告了一种由纳米级导体两端的温差产生的基本电子噪声的测量结果，我们将其称为“δ-T噪声”。我们通过实验在原子和分子结中证明了这种噪声，并使用朗道尔形式理论对其进行了理论分析。我们的研究结果表明，δ-T噪声与热噪声和电压激活的散粒噪声不同。与热噪声一样，它纯粹源于热，但δ-T噪声仅在非平衡状态下产生。δ-T噪声和标准散粒噪声具有相同的分配起源，但由不同的刺激激活。我们推断，δ-T噪声与热噪声相结合可用于检测纳米级导体两端的温差，而无需制造复杂的局部探针。因此，它可以极大地促进对纳米级热传输的研究。在现代电子学背景下，电子元件之间经常会无意地产生温差。在这些情况下，考虑δ-T噪声的贡献对于量子极限下高效纳米级电子学的设计可能至关重要。
