Localization effect in a two-dimensional superconducting network without disorder

The superconducting properties of a two-dimensional superconducting wire ne twork 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 cel l, For this particular magnetic field, the observed vortex state configurat ion is highly disordered. (C) 2001 Elsevier Science B.V. All rights reserve d.