Observation of Quantum Oscillations between a Josephson Phase Qubit and a Microscopic Resonator Using Fast Readout
Ken B. Cooper, Matthias Steffen, Robert McDermott, Raymond W. Simmonds, Seongshik Oh, Dustin A. Hite, D. P. Pappas, John M. Martinis · Physical Review Letters · 2004
We have detected coherent quantum oscillations between Josephson phase qubits and critical-current fluctuators by implementing a new state readout technique that is an order of magnitude faster than previous methods. These results reveal a new aspect of the quantum behavior of Josephson junctions, and they demonstrate the means to measure two-qubit interactions in the time domain. The junction-fluctuator interaction also points to a possible mechanism for decoherence and reduced fidelity in superconducting qubits.