Preprint

FZJ-2025-04654

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Surface-Code Hardware Hamiltonian

Xu, X. (Corresponding author)FZJ* ; Kaur, K.FZJ* ; Vignes, C. ; Ansari, M. H.FZJ* ; Martinis, J. M.

2025

This record in other databases:

Report No.: arXiv:2507.06201

Abstract: We present a scalable framework for accurately modeling many-body interactions in surface-code quantum processor units (QPUs). Combining a concise diagrammatic formalism with high-precision numerical methods, our approach efficiently evaluates high-order, long-range Pauli string couplings and maps complete chip layouts onto exact effective Hamiltonians. Applying this method to surface-code architectures, such as Google's Sycamore lattice, we identify three distinct operational regimes: computationally stable, error-dominated, and hierarchy-inverted. Our analysis reveals that even modest increases in residual qubit-qubit crosstalk can invert the interaction hierarchy, driving the system from a computationally favorable phase into a topologically ordered regime. This framework thus serves as a powerful guide for optimizing next-generation high-fidelity surface-code hardware and provides a pathway to investigate emergent quantum many-body phenomena.

Note: 18 pages, 12 figures

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Contributing Institute(s):

1. Theoretische Nanoelektronik (PGI-2)

Research Program(s):

1. 5221 - Advanced Solid-State Qubits and Qubit Systems (POF4-522) (POF4-522)

Appears in the scientific report 2025

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