Magnetic oscillations of critical current in intrinsic Josephson-junction stacks

Abstract

A key phenomenon related to the Josephson effect is oscillations of the different properties of superconducting tunneling junctions with magnetic field. We consider magnetic oscillations of the critical current in stacks of intrinsic Josephson junctions, which are realized in mesas fabricated from layered high-temperature superconductors. The oscillation behavior is very different from the case of a single junction. Depending on the stack lateral size, oscillations may have either the period of half a flux quantum per junction (wide-stack regime) or one flux quantum per junction (narrow-stack regime). We study in detail the crossover between these two regimes. The typical size separating the regimes is proportional to the magnetic field, meaning that the crossover can be driven by the magnetic field. In the narrow-stack regime the lattice structure experiences a periodic series of phase transitions between aligned rectangular configurations and triangular configurations. Triangular configurations in this regime are realized only in narrow regions near magnetic-field values corresponding to an integer number of flux quanta per junction.

Source-reported materials — not catalogue approval

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