Critical current of superconducting wire networks: experimental study

We report the first detailed measurements on the critical current of periodic superconducting wire networks as a function of an external magnetic field. Sharp spikes are observed at integer and fractional reduced magnetic fluxes φ/φ0, where φ is the magnetic flux per unit cell of the network. The experimental results are discussed in terms of the depairing current for the 2D array. An approach based upon the band properties of the paired electrons on the underlying lattice is proposed. This model explains the main features of the field and temperature dependence of the critical current without referring to pinning effects of the vortex lattice