Nature 560, 209–213 (2018)

Nature 560, 204–208 (2018)

The deterministic arrangement of atoms in two dimensions promises opportunities for quantum electronics. In addition to tuning conductors into insulators, researchers have long sought to take control over the quantum properties of 2D materials, as their synthesis has reached atomistic precision. Now, Oliver Gröning and co-workers have designed graphene nanoribbons, in which the electronic structure of sub-elements features local quantum states that can be connected in a chain to form a unique band structure.

Synthesizing the nanoribbons from molecular building blocks on a single crystalline surface, Gröning et al. demonstrated that the exact adjustment of the width of the structure is key to the formation of stable and coupled topologically protected quantum states. Such nanoribbons might find applications as nanotransistors, or as qubits for quantum computers. In a related report, Daniel Rizzo and colleagues made use of the same principle of band engineering, thus demonstrating the power of tailor-made topological interface states.