Phase shifting control for IQ separation in qubit state tomography

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review

2 Scopus Citations
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Detail(s)

Original languageEnglish
Article number19
Journal / PublicationQuantum Information Processing
Volume23
Online published6 Jan 2024
Publication statusPublished - 2024

Abstract

Achieving high fidelity in the readout of superconducting qubits through homodyne detection requires a sufficient signal-to-noise ratio during detection, the data of which ideally land on a circular path in the IQ quadrature plane. Extraneous imbalances in the IQ mixer deform the path into an ellipse and decrease the detection fidelity. We present a novel approach that utilizes phase-shift control to rotate the state vectors on the IQ plane. By optimizing the phase shift, the detection data are symmetrically distributed about the elliptical minor axis where the readout signal-to-noise ratio is maximized. An 11% enhancement in the readout signal-to-noise ratio has been demonstrated through both theoretical analysis and experimental verification, resulting in improved fidelity in qubit state tomography. © The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature 2023.

Research Area(s)

  • Phase shifting, Qubit state tomography, Superconducting qubits

Citation Format(s)

Phase shifting control for IQ separation in qubit state tomography. / You, Ziyang; Chio, Chi-Hou; Hoi, Io-Chun et al.
In: Quantum Information Processing, Vol. 23, 19, 2024.

Research output: Journal Publications and ReviewsRGC 21 - Publication in refereed journalpeer-review