Microscopic Model of Critical Current Noise in Josephson Junctions

Abstract

We present a simple microscopic model to show how fluctuating two--level systems in the Josephson junction tunnel barrier of thickness $L$ can modify the potential energy of the barrier and produce critical current noise spectra. We find low frequency $1/f$ noise that goes as $L^5$. Our values are in good agreement with recent experimental measurements of critical current noise in Al/AlO${}_x$/Al Josephson junctions. We also investigate the sensitivity of the noise on the nonuniformity of the tunnel barrier.

4 pages, 3 figures

References in corpus (2)

• Low- and high-frequency noise from coherent two-level systems
• Low-frequency Noise in Josephson Junctions for Superconducting Qubits

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