Demonstration of Two-Dimensional Connectivity for a Scalable Error-Corrected Ion-Trap Quantum Processor Architecture

Physical Review X, vol. 15

Abstract

A major hurdle for building a large-scale quantum computer is increasing the number of qubits while maintaining connectivity between them. In trapped-ion devices, this connectivity can be achieved by moving subregisters consisting of a few ions across the processor. Here, we focus on an architecture, which we refer to as the quantum spring array (QSA), that is based on a rectangular two-dimensional lattice of linear strings of ions. Connectivity between adjacent ion strings can be controlled by adjusting their separation. This requires control of trapping potentials along two directions, one along the axis of the ion string and one radial to it. In this work, we investigate key elements of the QSA architecture along both directions: We show that the coupling rate between neighboring lattice sites increases with the number of ions per site and the motion of the coupled system can be resilient to electrical noise, both being key requisites for fast and high-fidelity quantum gate operations. The coherence of the coupling is assessed and an entangling gate between qubits stored in radially separated trapping regions is demonstrated. Moreover, we demonstrate control over radio-frequency signals to adjust the radial separation, and thus the coupling rate, between strings. We further present constructions for the implementation of parallelized, transversal gate operations, and map the QSA architecture to code primitives for fault-tolerant quantum error correction, providing a step towards a quantum processor architecture that is optimized for large-scale operation.

Authors 14

1. Marco Valentini corresponding

   Universität Innsbruck

   Affiliation as printed

   Universität Innsbruck

2. Martin W. van Mourik corresponding

   Universität Innsbruck

   Affiliation as printed

   Universität Innsbruck

3. Friederike Butt Aachen

   Forschungszentrum Jülich · RWTH Aachen University

   Affiliation as printed

   Forschungszentrum Jülich

   RWTH Aachen University

4. Matthias Dietl

   Universität Innsbruck · Infineon Technologies (Austria)

   Affiliation as printed

   Infineon Technologies Austria

   Universität Innsbruck

5. M. Pfeifer

   Universität Innsbruck · Infineon Technologies (Austria)

   Affiliation as printed

   Infineon Technologies Austria

   Universität Innsbruck

6. Fabian Anmasser

   Universität Innsbruck · Infineon Technologies (Austria)

   Affiliation as printed

   Infineon Technologies Austria

   Universität Innsbruck

7. Yves Colombe

   Infineon Technologies (Austria)

   Affiliation as printed

   Infineon Technologies Austria

8. Clemens Rössler

   Infineon Technologies (Austria)

   Affiliation as printed

   Infineon Technologies Austria

9. Philip C. Holz

   Alpine Quantum Technologies (Austria)

   Affiliation as printed

   Alpine Quantum Technologies GmbH

10. R. Blatt

    Universität Innsbruck · Institute for Quantum Optics and Quantum Information Innsbruck · Alpine Quantum Technologies (Austria)

    Affiliation as printed

    Alpine Quantum Technologies GmbH

    Institute for Quantum Optics and Quantum Information

    Universität Innsbruck

11. A. Bermúdez

    Universidad Autónoma de Madrid

    Affiliation as printed

    Universidad Autónoma de Madrid

12. Markus Michael Müller Aachen

    Forschungszentrum Jülich · RWTH Aachen University

    Affiliation as printed

    Forschungszentrum Jülich

    RWTH Aachen University

13. Thomas Monz

    Universität Innsbruck · Alpine Quantum Technologies (Austria)

    Affiliation as printed

    Alpine Quantum Technologies GmbH

    Universität Innsbruck

14. Philipp Schindler

    Universität Innsbruck

    Affiliation as printed

    Universität Innsbruck