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  • Open Access

Conveyor-belt superconducting quantum computer

Francesco Cioni1,*,†, Roberto Menta2,1,*,‡, Riccardo Aiudi2, Marco Polini2,3, and Vittorio Giovannetti1,2

  • *These author contributed equally to this work.
  • †Contact author: francesco.cioni@sns.it
  • ‡Contact author: rmenta@planckian.co
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Phys. Rev. A 113, 012439 – Published 26 January, 2026

DOI: https://doi.org/10.1103/6zzp-ctyx

Abstract

The processing unit of a solid-state quantum computer consists of an array of coupled qubits, each locally driven with on-chip microwave lines that route control signals to the qubits in order to perform logical operations. This approach to quantum computing comes with two major problems. On the one hand, it greatly hampers scalability towards fault-tolerant quantum computers, which are estimated to need a number of qubits—and therefore driving lines—on the order of 106. On the other hand, these lines are a source of electromagnetic noise, exacerbating frequency crowding and crosstalk, while also contributing to power dissipation inside the dilution fridge. We here tackle these two challenges by presenting a quantum processing unit (QPU) for a universal quantum computer which is globally (rather than locally) driven. Our QPU relies on a closed loop of superconducting qubits with always-on ZZ interactions which we dub the “conveyor belt.” Notably, this architecture requires only O(N) physical qubits to run a computation on N computational qubits, in contrast to previous O(N2) proposals for global quantum computation. Universality is achieved via the implementation of single-qubit gates and a one-shot Toffoli gate. The ability to perform multiqubit operations in a single step could vastly improve the fidelity and execution time of many algorithms.

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Outline

Information

Phys. Rev. A 113, 012439– Published 26 January, 2026
  • Received 17 March 2025
  • Accepted 9 January 2026
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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