A proposed superconducting circuit quantum annealer with fully programmable all-to-all coupling

A grand challenge for quantum annealing is the development of annealing hardware that allows fully programmable all-to-all connectivity between logical qubits, with the lowest possible overhead in physical resources. The LHZ [1] scheme achieves fully programmable all-to-all connectivity with a planar architecture that is amenable to implementation with superconducting circuits [2], but does so at a cost of O(N²) physical qubits to realize N logical qubits. We propose a novel architecture for a superconducting circuit quantum annealer that requires only N physical qubits to realize N logical qubits, and present analytical and numerical evidence that fully connected and programmable quantum annealers with N=1000 logical qubits can be constructed with technology that requires only modest improvements over what currently exists.

[1] W. Lechner, et al. Science Advances 1, 9, e1500838 (2015).
[2] S. Puri, et al. Nature Communications 8, 15785 (2017).