Quantum computing and condensed matter physics with microwave photons

Coherent control of a superconducting qubit with dynamically tunable qubit-cavity coupling

A. J. Hoffman, S. J. Srinivasan, J. M. Gambetta, and A. A. Houck

We demonstrate coherent control and measurement of a superconducting qubit coupled to a superconducting coplanar waveguide resonator with a dynamically tunable qubit-cavity coupling strength. Rabi oscillations are measured for several coupling strengths showing that the qubit transition can be turned off by a factor of more than 1500. We show how the qubit can still be accessed in the off state via fast flux pulses. We perform pulse delay measurements with synchronized fast flux pulses on the device and observe T1 and T2 times of 1.6 and 1.9 μs, respectively. This work demonstrates how this qubit can be incorporated into quantum architectures.