Current fluctuations in rough superconducting tunnel junctions

Article

关键词: MACROSCOPIC QUANTUM STATES;    ENERGY-GAP STRUCTURE;    JOSEPHSON-JUNCTION;    COUNTING STATISTICS;    ANDREEV REFLECTION;    CIRCUIT-THEORY;    SHOT-NOISE;    QUBITS;    SUPERPOSITION;    OSCILLATIONS;   

DOI  :  10.1103/PhysRevB.80.214536

来源: SCIE

【 摘 要 】

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.

【 授权许可】

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