Precision tomography of a three-qubit electron-nuclear quantum processor in silicon
ORAL · Invited
Abstract
Nuclear spins were among the first physical platforms to be considered for quantum information processing, because of their exceptional quantum coherence and atomic-scale footprint. However, their full potential for quantum computing has not yet been realized, due to the lack of methods to link nuclear qubits within a scalable device combined with multi-qubit operations with sufficient fidelity to sustain fault-tolerant quantum computation. Here we demonstrate universal quantum logic operations using a pair of ion-implanted 31P nuclei in a silicon nanoelectronic device. A nuclear two-qubit controlled-Z gate is obtained by imparting a geometric phase to a shared electron spin, and used to prepare entangled Bell states with fidelities up to 94.2(2.7)%. The quantum operations are precisely characterised using gate set tomography (GST) yielding one-qubit average gate fidelities up to 99.95(2)%, two-qubit average gate fidelity of 99.37(11)% and two-qubit preparation/measurement fidelities of 98.95(4)%. These three metrics indicate that nuclear spins in silicon are approaching the performance demanded in fault-tolerant quantum processors. We then demonstrate entanglement between the two nuclei and the shared electron by producing a Greenberger-Horne-Zeilinger three-qubit state with 92.5(1.0)% fidelity. Since electron spin qubits in semiconductors can be further coupled to other electrons or physically shuttled across different locations these results establish a viable route for scalable quantum information processing using nuclear spins.
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Publication:Mądzik, Mateusz T., Asaad, Serwan, et al. "Precision tomography of a three-qubit electron-nuclear quantum processor in silicon." arXiv preprint arXiv:2106.03082 (2021).
Presenters
Mateusz T Madzik
Delft University of Technology
University of New South Wales
QuTech and Kavli Institute of Nanoscience, Delft University of Technology
Authors
Mateusz T Madzik
Delft University of Technology
University of New South Wales
QuTech and Kavli Institute of Nanoscience, Delft University of Technology
Serwan Asaad
University of New South Wales
Akram Youssry
University of Technology Sydney
Benjamin Joecker
University of New South Wales
Kenneth M Rudinger
Sandia National Laboratories
Erik Nielsen
Sandia National Laboratories
Kevin C Young
Sandia National Laboratories
Timothy J Proctor
Sandia National Laboratories
Andrew D Baczewski
Sandia National Laboratories
Arne Laucht
University of New South Wales
Vivien Schmitt
CEA grenoble
CEA Grenoble
University of New South Wales
Fay E Hudson
University of New South Wales
Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia.
Kohei M Itoh
Keio Univ
School of Fundamental Science and Technology, Keio University, Kohoku-ku, Yokohama, Japan.
Keio University
Alexander M Jacob
School of Physics, University of Melbourne, Parkville VIC 3010, Australia
University of Melbourne
Brett C Johnson
University of Melbourne
David N Jamieson
School of Physics, University of Melbourne, Parkville VIC 3010, Australia
University of Melbourne
School of Physics, University of Melbourne, Melbourne, VIC 3010, Australia.
Andrew S Dzurak
University of New South Wales
Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia.
Christopher Ferrie
University of Technology Sydney
Robin J Blume-Kohout
Sandia National Laboratories
Andrea Morello
School of Electrical Engineering and Telecommunications, UNSW Sydney, Sydney NSW 2052, Australia
School of Electrical Engineering and Telecommunications, UNSW Sydney
University of New South Wales
Centre for Quantum Computation and Communication Technology, School of Electrical Engineering and Telecommunications, UNSW Sydney, New South Wales 2052, Australia.
