Fig. 3: Quantum Zeno dynamics.

a Evolution of the squared mean amplitude ∣〈â〉∣² in the mode as a function of the pump amplitude η for two different bias voltages. In the absence of Zeno effect, ∣〈â〉∣² is quadratic with the pump amplitude (green data). When the voltage lies in the range where the quantum Zeno dynamics limits the dynamic to one of a two-level system, we observe a clear saturation (blue data). The solid red line shows the prediction of a master equation taking into account the different absorption rates for different Fock states (see SI). The dashed line shows the expectation for an ideal two-level system. The calibration of the measured intensity is detailed in the SI. b Evolution of the power broadening Γ as a function of the pump amplitude. The resonance spectra shown in the inset are fitted using the usual formula for a two-level system, which predicts a fwhm \(\sqrt{{\kappa }^{2}+2{{{\Gamma }}}^{2}}\) (see SI), where κ is the total loss rate. Power broadening is important in the case of Zeno dynamics (blue data) and negligible otherwise, except at very high power (green data). The solid and dashed lines show the result of the master equation simulation and the expectation for an ideal two-level system.