Field induced Kosterlitz-Thouless transition in two-dimensional array of Nb-Al'O IND.x'-Nb Josephson junctions

We present recent results on the magnetic field dependence of current–voltage characteristics (CVC) for an artificially prepared two-dimensional array of unshunted Nb–AlOx–Nb Josephson junctions. The results obtained from the measured CVC and critical current IC(T,H)IC(T,H) differential magnetoresistance (DMR) View the MathML sourceR(T,H)=[dV/dI]I=IC(T,H) of the array are found to exhibit behavior compatible with field induced Kosterlitz–Thouless transition describing unbinding of vortex–antivortex pairs under applied magnetic field.CNPqCAPESFAPES