We present recent results on the magnetic field dependence of currentvoltage characteristics (CVC) for an artificially prepared two-dimensional array of unshunted NbAlOxNb Josephson junctions. The results obtained from the measured CVC and critical current IC(T,H) differential magnetoresistance (DMR) R(T,H)=[dVdI]I=IC(T,H) of the array are found to exhibit behavior compatible with field induced KosterlitzThouless transition describing unbinding of vortexantivortex pairs under applied magnetic field.
Bibliographical noteFunding Information:
We are indebted to R.S. Newrock, P. Barbara and C.J. Lobb for helpful discussions and for providing SIS samples. This work has been financially supported by the Brazilian agencies CNPq, CAPES and FAPESP.
- D. Currentvoltage characteristics
- D. Differential magnetoresistance
- D. Josephson junction arrays
- D. KosterlitzThouless transition