Instituto de Ciencia de Materiales de Madrid
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Time-resolved measurement of a charge qubit

Georg M. Reuther, David Zueco, Peter Hänggi, and Sigmund Kohler
Phys. Rev. Lett. 102, 033602 (2009)

We propose a scheme for monitoring coherent quantum dynamics with good time-resolution and low backaction, which relies on the response of the considered quantum system to high-frequency ac driving. An approximate analytical solution of the corresponding quantum master equation reveals that the phase of an outgoing signal, which can directly be measured in an experiment with lock-in technique, is proportional to the expectation value of a particular system observable. This result is corroborated by the numerical solution of the master equation for a charge qubit realized with a Cooper-pair box, where we focus on monitoring coherent oscillations.
arXiv:0806.2786 [cond-mat]

[ICMM-CSIC] [Condensed Matter Theory]
last modified: 15.3.2024 by Sigmund Kohler