Low crosstalk in a scalable superconducting quantum lattice

Journal article

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.

Authors: Alghadeer, M; Cao, S; Fasciati, SD; Piscitelli, M; Gow, PC

• Publication status: Published
• Peer review status: Peer reviewed
• Publisher: SpringerOpen
• Journal: EPJ Quantum Technology
• Volume: 13
• Issue: 1
• Article number: 19
• Publication date: 2026-01-26
• Acceptance date: 2026-01-05
• DOI: 10.1140/epjqt/s40507-026-00465-3
• EISSN: 2196-0763
• ISSN: 2662-4400
• Language: English
• Keywords: Quantum computing; Superconducting qubits; Scalable quantum devices; Quantum algorithms