High fidelity qubit readout with the superconducting low-inductance undulatory galvanometer microwave amplifier

Journal Article · Mon Apr 14 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4871088· OSTI ID:22262607

Hover, D.; Zhu, S.; Thorbeck, T.; Ribeill, G. J.; Sank, D.; Kelly, J.; Barends, R.; Martinis, John M. ^[1]

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1. Department of Physics, University of California, Santa Barbara, California 93106 (United States)

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.

• OSTI ID: 22262607
• Journal Information: Applied Physics Letters, Vol. 104, Issue 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
GALVANOMETERS
INDUCTANCE
MICROWAVE AMPLIFIERS
PHOTONS
QUBITS
SIGNAL-TO-NOISE RATIO