IMAGING OF VORTICES IN 2D SUPERCONDUCTING ARRAYS - MAGNETIC DECORATION AND OTHER METHODS

Direct observation of vortex configurations has been in the last years an interesting challenge to understanding frustration, coherence and interaction effects in superconducting arrays. Recently, magnetic deco ration technique has been used to image vortices in wire arrays. The v ortex configuration was found to depend strongly on the frustration. L arge domains of commensurate states were observed near low rational fr ustration. We discuss the observed patterns in terms of the models of ground state vortex configurations in classical arrays. With increasin g the width of the wires the frustration effect disappears. We present new results on multiquanta vortices in an array of microholes and an extension of this method to various superconducting arrays. A brief re view is given on the recent developments on vortex imaging by other di rect methods, mostly scanning probes microscopy, which gives access to dynamical properties of vortices.