We describe a simple and efficient scheme for the readout of a tunable flux qubit, and present preliminary experimental tests for the preparation, manipulation and final readout of the qubit state, performed in incoherent regime at liquid Helium temperature. The tunable flux qubit is realized by a double SQUID with an extra Josephson junction inserted in the large superconducting loop, and the readout is performed by applying a current ramp to the junction and recording the value for which there is a voltage response, depending on the qubit state. This preliminary work indicates the feasibility and efficiency of the scheme.
@article{arxiv.cond-mat/0506663,
title = {Superconducting tunable flux qubit with direct readout scheme},
author = {Fabio Chiarello and Pasquale Carelli and Maria Gabriella Castellano and Carlo Cosmelli and Lorenzo Gangemi and Roberto Leoni and Stefano Poletto and Daniela Simeone and Guido Torrioli},
journal= {arXiv preprint arXiv:cond-mat/0506663},
year = {2009}
}