Computing Library › Glossary
Glossary

Quantum Annealing

A quantum optimization approach that seeks low-energy states by slowly evolving a quantum system.

Definition

Quantum annealing solves optimization problems by encoding them as the energy landscape of a quantum system, then slowly evolving the system so it settles into a low-energy state that represents a good solution. Quantum tunneling can help escape local minima that trap classical methods.

Annealers are far more numerous in qubit count than gate-model machines but far more limited in what they compute, and independent studies have struggled to show a clear, general speedup over the best classical heuristics. Their value remains problem-specific and actively debated.

The commercial availability of large annealers has produced a substantial body of empirical study, and the consistent finding is that a clear, general advantage over the best classical heuristics has been hard to establish. Advantages, where reported, tend to be problem-specific and sensitive to how the problem is mapped onto the hardware's limited connectivity. This makes annealing a case study in the care needed to evaluate quantum performance claims.

Contrast with gate model

Why it matters

Annealing targets the combinatorial optimization problems common in scheduling, logistics, and design. Whether it offers a real advantage over strong classical solvers such as simulated annealing remains an open, problem-dependent question.

Fusion connection

Combinatorial layout and scheduling problems in engineering are candidate annealing applications, evaluated by Kronos against classical optimizers on the same problem before any adoption.