We have constructed a new type of amplifier whose primary purpose is the readout of superconducting quantum bits. It is based on the transition of an RF-driven Josephson junction between two distinct oscillation states near a dynamical bifurcation point. The main advantages of this new amplifier are speed, high-sensitivity, low back-action, and the absence of on-chip dissipation. Using pulsed microwave techniques, we demonstrate bifurcation amplification in nanofabricated Al junctions and verify that the performance predicted by theory is attained.
@article{arxiv.cond-mat/0507248,
title = {The Josephson Bifurcation Amplifier for Quantum Measurements},
author = {I. Siddiqi and R. Vijay and F. Pierre and C. M. Wilson and L. Frunzio and M. Metcalfe and C. Rigetti and M. H. Devoret},
journal= {arXiv preprint arXiv:cond-mat/0507248},
year = {2007}
}
Comments
To be published in the proceedings of the 2004 MQC2 conference