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arXiv · 1312.7579

High Fidelity Qubit Readout with the Superconducting Low-Inductance Undulatory Galvanometer Microwave Amplifier

D. Hover·S. Zhu·T. Thorbeck·G. J. Ribeill·D. Sank·J. Kelly·R. Barends·John M. Martinis·R. McDermott
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Abstract

We describe the high fidelity dispersive measurement of a superconducting qubit using a microwave amplifier based on the Superconducting Low-inductance Undulatory Galvanometer (SLUG). The SLUG preamplifier achieves gain of 19 dB and yields a signal-to-noise ratio improvement of 9 dB over a state-of-the-art HEMT amplifier. We demonstrate a separation fidelity of 99% at 700 ns compared to 59% with the HEMT alone. The SLUG displays a large dynamic range, with an input saturation power corresponding to 700 photons in the readout cavity.

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D. Hover, S. Zhu, T. Thorbeck, G. J. Ribeill, D. Sank, J. Kelly, R. Barends, John M. Martinis, R. McDermott. 2013-12-29. High Fidelity Qubit Readout with the Superconducting Low-Inductance Undulatory Galvanometer Microwave Amplifier. https://doi.org/10.1063/1.4871088

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