Summary: Magnetic oscillations of critical current in intrinsic Josephson-junction stacks
A. E. Koshelev
Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439, USA
Received 22 September 2006; revised manuscript received 22 February 2007; published 26 June 2007
A key phenomenon related to the Josephson effect is oscillations of the different properties of supercon-
ducting 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 corre-
sponding to an integer number of flux quanta per junction.
DOI: 10.1103/PhysRevB.75.214513 PACS number s : 74.50. r, 74.72.Hs, 74.81.Fa, 74.25.Qt
Layered high-temperature superconducting materials,
such as Bi2Sr2CaCu2Ox BSCCO , are composed of super-
conducting cuprate layers coupled by Josephson interaction.