Quantum phase slip dynamics in Josephson junction chains

In contrast to Josephson Junctions (JJ) which show a tunneling of superconducting charge carriers, phase-slip junctions are characterized by a tunneling of the superconducting phase. It has been shown theoretically1 that phase-slip junctions can be realized by including a JJ in a high impedance environment or by using a long chain of JJ's. Phase-slip junctions could have an important metrological application, as under microwave irradiation they are expected to show plateaus of constant current at multiples of the applied microwave frequency. This frequency to current conversion could be used to implement a current standard. We present measurements of the current voltage characteristics of JJ chains of different lengths. For shorter chains we observe a zero current state that we attribute to quantum phase-slip dynamics2 in the chain. A superconducting like behavior is observed for longer chain that we understand by taking into account the excitation of standing electromagnetic waves in the chain.