Fig. 4.

Continuous wave spectroscopy of the $\mathit{\lambda }/4$ resonator at 7.5 GHz in the single photon regime, with the qubit tuned to the ‘sweet spot’ of ${\mathit{\nu }}_{01}=8.501\mathrm{GHz}$. a Transmission past the resonator at 7.52 GHz and b resonance frequency as a function of probe power, showing the shift between the dressed $|0⟩$ state of the qubit+resonator system (at powers below −110 dBm) and the bare resonator frequency (at powers above −90 dBm) for a qubit–resonator detuning of 990 MHz (Color figure online)