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arXiv 2402.09093cond-mat.supr-con
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超导量子干涉滤波器阵列中结临界电流无序的影响

Effect of junction critical current disorder in superconducting quantum interference filter arrays

K. -H. Müller, E. E. Mitchell

AI总结:

本研究通过实验与理论建模分析了77 K下YBCO薄膜SQIF阵列的性能,发现考虑50%临界电流无序的模型与实验数据吻合,揭示了临界电流无序对电压调制深度的影响,并证实了YBCO薄膜在SQIF阵列中的应用潜力。

摘要:

在本研究中,我们研究了在77 K温度下由YBCO薄膜制备的两个2D超导量子干涉滤波器(SQIF)阵列的性能。每个阵列由6个并联的Josephson结(JJs)和167个串联的JJs组成。我们进行了实验和理论分析,测量了阵列对施加磁场的电压响应及其电压与偏置电流的特性。为了正确建模平面阵列布局,我们的理论模型使用了流函数方法,并在JJs中包含了Johnson噪声。为了实用性,该模型进一步将阵列的超导电流密度分为Meissner电流、循环电流和偏置电流部分。由于YBCO薄膜的制备工艺无法产生完全相同的JJ临界电流,我们假设对数正态分布来建模JJ临界电流无序。我们的模型预测,在JJ临界电流扩展为50%的情况下,与我们的实验数据非常吻合。使用我们的模型,我们能够研究电压调制深度对临界电流无序和London穿透深度的依赖性。我们还分析了观察到的电压与磁场特性的反射不对称性,这可能为临界电流无序的程度提供见解。总体而言,我们的研究结果表明,尽管YBCO薄膜的制备工艺中存在固有的临界电流无序,但其在SQIF阵列中的应用前景广阔。我们的研究强调了理论建模在理解超导器件性能方面的重要性,并提供了可为未来SQIF阵列设计提供参考的见解。

英文摘要:

In this study, we investigated the performance of two 2D superconducting quantum interference filter (SQIF) arrays fabricated from YBCO thin films at a temperature of 77 K. Each array consisted of 6 Josephson junctions (JJs) in parallel and 167 in series. We conducted both experimental and theoretical analyses, measuring the arrays' voltage responses to an applied magnetic field and their voltage versus bias-current characteristics. To properly model the planar array layouts, our theoretical model used the stream function approach and also included the Johnson noise in the JJs. The model further divides the superconducting current density of the arrays into its Meissner current, circulating current, and bias current parts for practicality. Since the fabrication process of YBCO thin films cannot produce identical JJ critical currents, we assumed a log-normal distribution to model the JJ critical current disorder. Our model predictions, with a JJ critical current spread of 50%, agreed well with our experimental data. Using our model, we were able to study the dependence of the voltage modulation depth on critical current disorder and London penetration depth. We also analyzed the observed reflection asymmetries of the voltage versus magnetic field characteristics, which might provide insight into the degree of critical current disorder. Overall, our findings suggest that the use of YBCO thin films in SQIF arrays is promising, despite the critical current disorder inherent in their fabrication process. Our study highlights the importance of theoretical modeling in understanding the performance of superconducting devices and provides insights that could inform the design of future SQIF arrays.

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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