A quantum annealing architecture with all-to-all connectivity from local interactions

TLDR

Quantum annealers aim to solve NP‑complete optimization problems by encoding them in Ising interactions between qubits, but achieving full programmable all‑to‑all connectivity while maintaining quasi‑local interactions remains a fundamental challenge. The authors propose a scalable architecture that achieves full connectivity using only local interactions. Their design encodes the problem in local fields on an extended set of qubits, redundantly stores the solution in a fault‑tolerant manner, interprets the system as a lattice gauge theory with gauge‑mediated long‑range interactions, and can be implemented on platforms such as superconducting qubits, NV centers, quantum dots, and atomic systems.

Abstract

Quantum annealers are physical devices that aim at solving NP-complete optimization problems by exploiting quantum mechanics. The basic principle of quantum annealing is to encode the optimization problem in Ising interactions between quantum bits (qubits). A fundamental challenge in building a fully programmable quantum annealer is the competing requirements of full controllable all-to-all connectivity and the quasi-locality of the interactions between physical qubits. We present a scalable architecture with full connectivity, which can be implemented with local interactions only. The input of the optimization problem is encoded in local fields acting on an extended set of physical qubits. The output is-in the spirit of topological quantum memories-redundantly encoded in the physical qubits, resulting in an intrinsic fault tolerance. Our model can be understood as a lattice gauge theory, where long-range interactions are mediated by gauge constraints. The architecture can be realized on various platforms with local controllability, including superconducting qubits, NV-centers, quantum dots, and atomic systems.