Inhomogeneous Josephson junction chains: a superconducting meta-material for superinductance optimization
1 Laboratoire de Physique et Modélisation des Milieux Condensés, Université de Grenoble-Alpes and CNRS, 25 Avenue des Martyrs, 38042 Grenoble, France
2 Institut Néel, Université de Grenoble-Alpes and CNRS, 25 Avenue des Martyrs, 38042 Grenoble, France
a e-mail: email@example.com
Received: 19 September 2016
Revised: 3 January 2017
Published online: 25 May 2017
We report a theoretical study of the low-frequency impedance of a Josephson junction chain whose parameters vary in space. Our goal is to find the optimal spatial profile which maximizes the total inductance of the chain without shrinking the low-frequency window where the chain behaves as an inductor. If the spatial modulation is introduced by varying the junction areas, we find that the best result is obtained for a spatially homogeneous chain, reported earlier in the literature. An improvement over the homogeneous result can be obtained by representing the junctions by SQUIDs with different loop areas, so the inductances can be varied by applying a magnetic field. Still, we find that this improvement becomes less important for longer chains.
© The Author(s) 2017
Open Access This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.