https://doi.org/10.1140/epjqt/s40507-026-00465-3
Research
Low crosstalk in a scalable superconducting quantum lattice
1
Department of Physics, Clarendon Laboratory, University of Oxford, OX1 3PU, Oxford, UK
2
Optoelectronics Research Centre, University of Southampton, SO17 1BJ, Southampton, UK
a
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b
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c
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Received:
11
November
2025
Accepted:
5
January
2026
Published online:
26
January
2026
Abstract
Superconducting quantum circuits are a key platform for advancing quantum information processing and simulation. Scaling efforts currently encounter challenges such as Josephson-junction fabrication yield, design frequency targeting, and long-range crosstalk arising both from spurious microwave modes and intrinsic interactions between qubits. We demonstrate a scalable 4x4 square lattice with low crosstalk, comprising 16 fixed-frequency transmon qubits with nearest-neighbor capacitive coupling that is implemented in a tileable, 3D-integrated circuit architecture with off-chip inductive shunting to mitigate spurious enclosure modes. We report on the design and comprehensive characterization, and show that our implementation achieves targeted device parameters with very low frequency spreads, long-range parasitic couplings and simultaneous single-qubit gate errors across the device. Our results provide a promising pathway toward a scalable superconducting square lattice topology for quantum error correction and simulation.
Key words: Superconducting qubits / Scalable quantum devices / Quantum algorithms / Quantum computing
© The Author(s) 2026
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