Year: 2026
Type: article
Abstract: We present a scalable framework for accurately modeling many-body interactions in surface-code quantum processing units. 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 interaction regimes: computationally stable phase, error-dominated phase, and hierarchy-inverted phase. 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.
Source: npj Quantum Information
Authors: Xuexin Xu, Kuljeet Kaur, Chloé Vignes, John M. Martinis, Mohammad H. Ansari
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,290
OpenAlex ID: W4416062421