2008/08/27 by Georg Heinrich, Frank K. Wilhelm, F. K. Wilhelm
Computer Science · Physics and Astronomy · #Physics of Superconductivity and Magnetism #Quantum Information and Cryptography #Quantum and electron transport phenomena #cond-mat.mes-hall
paper · pdf · doi:10.1103/physrevb.80.214536
published as Phys. Rev. B 80, 214536 (2009) · 11 pages, 11 figures
arxiv created 2008/08/27 · openalex publication_date 2009/12/30 · arxiv updated 2010/05/13 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Intrinsic noise is known to be ubiquitous in Josephson junctions. We introduce a rough tunnel junction model characterized by a very small number of pinholes---transport channels possessing a transmission coefficient close to unity and analyze its transport properties. Although it may still have just a small total leakage current, it can lead to enormous current fluctuations in the low-voltage regime. We show that even fully transparent transport channels between superconductors contribute to shot noise due to the uncertainty in the number of Andreev cycles. We discuss shot-noise enhancement by multiple Andreev reflection in such a junction and investigate whether pinholes might contribute as a microscopic mechanism of two-level current fluctuators. We discuss the connection of these results to the junction resonators observed in Josephson phase qubits.