Quantum Zeno effect in the strongmeasurement regime of circuit quantum electrodynamics

Weobserve the quantumZeno effect—where the act ofmeasurement slows the rate of quantum state transitions—in a superconducting qubit using linear circuit quantum electrodynamics readout and a near-quantum-limited following amplifier. Under simultaneous strongmeasurement and qubit drive, the qubit undergoes a series of quantum jumps between states. These jumps are visible in the experimentalmeasurement record and are analyzed usingmaximum likelihood estimation to determine qubit transition rates. The observed rates agree with both analytical predictions and numerical simulations. The analysismethods are suitable for processing general noisy random telegraph signals.