Voss Jan Nicolas, Schön Yannick, Wildermuth Micha, Dorer Dominik, Cole Jared H, Rotzinger Hannes, Ustinov Alexey V
Physikalisches Institut, Karlsruher Institut für Technologie, 76131 Karlsruhe, Germany.
Chemical and Quantum Physics, School of Science, RMIT University, Melbourne, Victoria 3000, Australia.
ACS Nano. 2021 Mar 23;15(3):4108-4114. doi: 10.1021/acsnano.0c08721. Epub 2021 Feb 17.
In systems with reduced dimensions, quantum fluctuations have a strong influence on the electronic conduction, even at very low temperatures. In superconductors, this is especially interesting, since the coherent state of the superconducting electrons strongly interacts with these fluctuations and therefore is a sensitive tool to study them. In this paper, we report on comprehensive measurements of superconducting nanowires in the quantum phase slip regime. Using an intrinsic electromigration process, we have developed a method to lower the nanowire's resistance and therefore eliminate quantum phase slips in small consecutive steps. We observe critical (Coulomb) blockade voltages and superconducting critical currents, in good agreement with theoretical models. Between these two regimes, we find a continuous transition displaying a nonlinear metallic-like behavior. The reported intrinsic electromigration technique is not limited to low temperatures, as we find a similar change in resistance that spans over 3 orders of magnitude also at room temperature. Aside from superconducting quantum circuits, such a technique to reduce the resistance may also have applications in modern electronic circuits.
在维度降低的系统中，即使在非常低的温度下，量子涨落也会对电子传导产生强烈影响。在超导体中，这一点尤其有趣，因为超导电子的相干态与这些涨落强烈相互作用，因此是研究它们的一个灵敏工具。在本文中，我们报告了在量子相位滑移 regime 中对超导纳米线的综合测量。通过一种本征电迁移过程，我们开发了一种方法来降低纳米线的电阻，从而以小的连续步骤消除量子相位滑移。我们观察到临界（库仑）阻塞电压和超导临界电流，与理论模型吻合良好。在这两种 regime 之间，我们发现了一个呈现非线性金属样行为的连续转变。所报道的本征电迁移技术不限于低温，因为我们发现在室温下电阻也有跨越 3 个数量级的类似变化。除了超导量子电路外，这种降低电阻的技术在现代电子电路中也可能有应用。
