Quantum-phase transition in 1D Josephson junction arrays

One-dimensional arrays of small capacitance SQUIDs have been studied experi mentally. The effective Josephson coupling between neighboring electrodes i s tunable in situ. The arrays can be tuned from a Josephson-like state, wit h low resistance and sharp critical current, to a Coulomb blockade state, w ith infinite resistance and sharp threshold voltage. A quantum phase transi tion occurs at the crossover between these two types of behavior, which is evident from an analysis of the temperature dependence of the zero bias res istance. (C) 2000 Elsevier Science B.V. All rights reserved.