Quantum trajectory approach to circuit QED: Quantum jumps and the Zeno effect

By Jay M. Gambetta, Alexandre Blais, M. Boissonneault, Andrew A. Houck, David I. Schuster, Steven M. Girvin. 2007

280 citations recorded by the source corpus.

We present a theoretical study of a superconducting charge qubit dispersively coupled to a transmission line resonator. Starting from a master equation description of this coupled system and using a polaron transformation, we obtain an exact effective master equation for the qubit. We then use quantum trajectory theory to investigate the measurement of the qubit by continuous homodyne measurement of the resonator out-field. Using the same porlaron transformation, a stochastic master equation for the conditional state of the qubit is obtained. From this result, various definitions of the measurement time are studied. Furthermore, we find that in the limit of strong homodyne measurement, typical quantum trajectories for the qubit exhibit a crossover from diffusive to jumplike behavior. Finally, in the presence of Rabi drive on the qubit, the qubit dynamics is shown to exhibit quantum Zeno behavior.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/a1c007a46ca920a40d93002b766c15085bb35947

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Citations in the corpus

Microwave photonics with superconducting quantum circuits (2017, methodology): “This shift can be used to perform a QND measurement on the qubit by probing the transmission of the resonator [6, 361].”
Experimental violation of a Bell’s inequality in time with weak measurement (2010, methodology): “Using a model similar to [19], we keep the form of the dispersive Hamiltonian unchanged but use a modified dispersive constant χ(n̄) = χ(0)(1− λn̄) yielding a modified conversion factor δV (n̄)(1 − λn̄).”
Demonstration of quantum volume 64 on a superconducting quantum computing system (2020, background): “Single qubits are dispersively read out by transversely coupled transmission line cavities [50].”