Abstract
We present a superconducting qubit for the circuit quantum electrodynamics architecture that has a tunable qubit-resonator coupling strength . This coupling can be tuned from zero to values that are comparable with other superconducting qubits. At , the qubit is in a decoherence-free subspace with respect to spontaneous emission induced by the Purcell effect. Furthermore, we show that in this decoherence-free subspace, the state of the qubit can still be measured by either a dispersive shift on the resonance frequency of the resonator or by a cycling-type measurement.
- Received 21 September 2010
DOI:https://doi.org/10.1103/PhysRevLett.106.030502
© 2011 American Physical Society