A braid of copper-colored cables surrounds an inconspicuous chip in the middle. You can see the Advantage2 quantum annealer from D-Wave. This quantum computer will soon be located at Florida Atlantic University in the USA. It can solve optimization problems where classic computers reach their limits.
A simple example of an optimization problem is finding the best route for a vehicle in the city. Only a few variables play a role, for example the length of the route or the current traffic situation. However, if you apply this problem to all traffic, it quickly becomes much more complex. Suddenly the routes of hundreds or thousands of vehicles have to be coordinated in order to keep the total travel time as short as possible.
Such tasks can be described as a landscape with hills and valleys. Each possible solution corresponds to a point on this landscape. The height of the point shows how good or bad this solution is. High hills represent unfavorable results with high costs, deep valleys represent particularly good solutions. The goal is to find the lowest point. Classic optimization methods often move gradually downhill, starting from a randomly chosen starting point. This approach can produce good results, but it involves risk. The process can end in a valley that is better than the surrounding area, but is far from the best solution. Higher hills then block the path, although there could be significantly deeper valleys beyond them.
A quantum annealer, in turn, uses the laws of quantum mechanics, i.e. the physics of the smallest particles. In this world, different rules apply than in everyday life. Particles can be in multiple states at the same time and can “tunnel” through valleys. This means they can move through barriers that are actually insurmountable. Quantum computers take advantage of these special properties. Instead of starting at a single point, the quantum annealer starts in many places on the landscape at the same time. In this way, he can pursue different solutions in parallel, move gradually towards better results and tunnel through valleys. This reduces the risk of getting stuck in an unfavorable solution early on.
Quantum annealers are used where many decisions have to be made at the same time. These include, for example, modeling molecules in the development of new drugs or better planning of supply chains or power grids. Florida Atlantic University has now installed the Advantage2 quantum annealer, a large, publicly accessible quantum computer directly on campus.