Realization and characterization of a squid flux qubit with a direct readout scheme

Abstract

We have proposed and realized a possible flux qubit based on a Niobium fully gradiometric double SQUID, with a direct readout scheme based on the insertion in the loop of a large Josephson junction. The first characterization performed at 4.2 K shows the capability of our device to discriminate the flux states in a very efficient way using a very simple scheme. Further work is required to study and optimize the effects of the readout on the flux state, together with a low temperature characterization, and finally, a study of the coherent behavior of this system. This work is partially supported by INFN under the project SQC (Superconducting Quantum Computing). © 2006 Springer Science+Business Media, Inc.