Quantum technologies utilize the unusual properties of the fundamental building blocks of matter. However, quantum states are fragile and their effects are difficult to grasp. Researchers at the Swiss Federal Laboratories for Materials Science and Technology (Empa) and their partners have now achieved a breakthrough: Using a kind of "quantum Lego", they have been able to exactly recreate a known theoretical quantum physics model in a synthetic material.
To produce such an artificial quantum material, the Empa researchers used tiny pieces of graphene. This nanographene molecule (known as Clar's goblet) consists of eleven carbon rings arranged in an hourglass-like shape. Due to this special shape, there is an unpaired electron at each end, each with an associated spin. It is practically a kind of nano-quantum Lego brick from which longer chains can be "plugged together".
The researchers have now linked the goblets on a gold surface to form chains. The two spins within a molecule are weakly linked, while the spins from molecule to molecule are strongly linked. The researchers were able to precisely manipulate the length of the chains, switch individual spins on and off and flip them from one state to another. They were able to show that theoretical models of quantum physics can be realized with nanographenes.
