Quantum annealing of a programmable Ising spin glass
In quantum annealing, a system with two non-commuting time dependent interactions is slowly evolved from an initial trivial state to a final complex classical state. If the evolution is slow enough, the final state can represent the solution of a difficult optimization problem encoded in the Hamiltonian. I will discuss experiments [1] on the D-Wave Advantage device, which consists of more than 5000 superconducting qubits, here programmed to one of the prototypical hard optimization problems; the 3D Ising spin glass. While the coherence times are not long enough to reach the ground state of large systems, results for short annealing times, up to 40 ns, exhibit Kibble-Zurek scaling in the system size and annealing time, showing that the system traverses the spin glass transition with the expected critical exponents. This field is now at an inflection point, where quantum annealing can address some problems beyond the reach of classical computers [2].
[1] A. King et al., Nature 617, 61 (2023).[2] A. King et al., arXiv:2403.00910.