Barone Carlo, Rotzinger Hannes, Voss Jan Nicolas, Mauro Costantino, Schön Yannick, Ustinov Alexey V, Pagano Sergio
Dipartimento di Fisica "E.R. Caianiello", Università degli Studi di Salerno, I-84084 Fisciano, Salerno, Italy.
CNR-SPIN Salerno, c/o Università degli Studi di Salerno, I-84084 Fisciano, Salerno, Italy.
Nanomaterials (Basel). 2020 Mar 14;10(3):524. doi: 10.3390/nano10030524.
The unusual superconducting properties of granular aluminum oxide have been recently investigated for application in quantum circuits. However, the intrinsic irregular structure of this material requires a good understanding of the transport mechanisms and, in particular, the effect of disorder, especially when patterned at the nanoscale level. In view of these aspects, electric transport and voltage fluctuations have been investigated on thin-film based granular aluminum oxide nanowires, in the normal state and at temperatures between 8 and 300 K. The nonlinear resistivity and two-level tunneling fluctuators have been observed. Regarding the nature of the noise processes, the experimental findings give a clear indication in favor of a dynamic random resistor network model, rather than the possible existence of a local ordering of magnetic origin. The identification of the charge carrier fluctuations in the normal state of granular aluminum oxide nanowires is very useful for improving the fabrication process and, therefore, reducing the possible sources of decoherence in the superconducting state, where quantum technologies that are based on these nanostructures should work.
最近，人们对粒状氧化铝的异常超导特性进行了研究，以用于量子电路。然而，这种材料固有的不规则结构需要深入了解其输运机制，特别是无序的影响，尤其是在纳米尺度上进行图案化时。鉴于这些方面，已经在基于薄膜的粒状氧化铝纳米线中研究了正常状态下以及8至300 K温度范围内的电输运和电压波动。观察到了非线性电阻率和双能级隧穿涨落器。关于噪声过程的性质，实验结果清楚地表明支持动态随机电阻网络模型，而不是可能存在磁起源的局部有序。识别粒状氧化铝纳米线正常状态下的电荷载流子涨落对于改进制造工艺非常有用，从而减少超导状态下可能的退相干源，基于这些纳米结构的量子技术应在超导状态下工作。
