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arXiv · 1005.0004

Improved Superconducting Qubit Readout by Qubit-Induced Nonlinearities

Maxime Boissonneault·J. M. Gambetta·Alexandre Blais
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Abstract

In dispersive readout schemes, qubit-induced nonlinearity typically limits the measurement fidelity by reducing the signal-to-noise ratio (SNR) when the measurement power is increased. Contrary to seeing the nonlinearity as a problem, here we propose to use it to our advantage in a regime where it can increase the SNR. We show analytically that such a regime exists if the qubit has a many-level structure. We also show how this physics can account for the high-fidelity avalanchelike measurement recently reported by Reed {\it et al.} [arXiv:1004.4323v1].

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Maxime Boissonneault, J. M. Gambetta, Alexandre Blais. 2010-09-07. Improved Superconducting Qubit Readout by Qubit-Induced Nonlinearities. https://doi.org/10.1103/physrevlett.105.100504

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