Passive superconducting circulator on a chip
Abstract
An on-chip microwave circulator that is compatible with superconducting devices is a key element for scale-up of superconducting circuits. Previous approaches to integrating circulators on chip involve either external driving that requires extra microwave lines or a strong magnetic field that would compromise superconductivity. Here we report the first proof-of-principle realisation of a passive on-chip circulator which is made from a superconducting loop interrupted by three notionally-identical Josephson junctions and is tuned with only DC control fields. Our experimental results shows evidence for nonreciprocal scattering, and excellent agreement with theoretical simulations. We also present a detailed analysis of quasiparticle tunneling in our device using a hidden Markov model. By reducing the junction asymmetry and utilising the known methods of protection from quasiparticles, we anticipate that Josephson-loop circulator will become ubiquitous in superconducting circuits.
Cite
@article{arxiv.2208.13339,
title = {Passive superconducting circulator on a chip},
author = {Rohit Navarathna and Dat Thanh Le and Andrés Rosario Hamann and Hien Duy Nguyen and Thomas M. Stace and Arkady Fedorov},
journal= {arXiv preprint arXiv:2208.13339},
year = {2023}
}