We report transport measurements on superconducting wire networks which provide the first
experimental evidence of a new localization phenomenon induced by magnetic field on a
2D periodic structure. In the case of a superconducting wave function this phenomenon
manifests itself as a depression of the network critical current and of the superconducting
transition temperature at a half magnetic flux quantum per tile. In addition, the strong
broadening of the resistive transition observed at this field is consistent with enhanced …

The superconducting properties of a two-dimensional superconducting wire network with a
new geometry have been measured as a function of the external magnetic field. The
extreme localization effect recently predicted for this periodic lattice is revealed as a
suppression of the critical current when the applied magnetic field corresponds to half a flux
quantum per unit cell. For this particular magnetic field, the observed vortex state
configuration is highly disordered.