arXiv subjects

L. Frunzio

Publications and source records attributed to L. Frunzio.

74 records · Page 5Linked to original sources

arXiv2003

An RF-Driven Josephson Bifurcation Amplifier for Quantum Measurements

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. Pulsed microwave reflection measurements on nanofabricated Al junctions show that actual devices attain the performance predicted by theory.

cond-mat.supr-con↗

arXiv2003

Direct Observation of Dynamical Switching between Two Driven Oscillation States of a Josephson Junction

We performed a novel phase sensitive microwave reflection experiment which directly probes the dynamics of the Josephson plasma resonance in both the linear and non-linear regime. When the junction was driven below the plasma frequency into the non-linear regime, we observed for the first time the transition between two different dynamical states predicted for non-linear systems. In our experiment, this transition appears as an abrupt change in the reflected signal phase at a critical excitation power.

cond-mat.supr-con↗