We have measured the current-voltage characteristics of a Josephson junction with tunable Josephson energy EJ embedded in an inductive environment provided by a chain of SQUIDs. Such an environment induces localization of the charge on the junction, which results in an enhancement of the zero-bias resistance of the circuit. We understand this result quantitatively in terms of the Bloch band dynamics of the localized charge. This dynamics is governed by diffusion in the lowest Bloch band of the Josephson junction as well as by Landau-Zener transitions out of the lowest band into the higher bands. In addition, the frequencies corresponding to the self-resonant modes of the SQUID array exceed the Josephson energy EJ of the tunable junction, which results in a renormalization of EJ, and, as a consequence, of the effective bandwidth of the lowest Bloch band.
@article{arxiv.1407.7728,
title = {Bloch band dynamics of a Josephson junction in an inductive environment},
author = {T. Weißl and G. Rastelli and I. Matei and I. M. Pop and O. Buisson and F. W. J. Hekking and W. Guichard},
journal= {arXiv preprint arXiv:1407.7728},
year = {2015}
}