With the new development, UC Berkeley researchers have shown how the process of linking two different types of nanoribbons together has the potential to yield a unique material. This material can immobilize single electrons at the junction where ribbon segments.
For this to happen the electron states of two graphene nanoribbon pieces need to be different. Working on this, researchers have demonstrated how the junctions of nanoribbons having the correct state can become occupied by individual localized electrons.
The resultant application is a nanoribbon formed of alternating ribbon strips of differing widths. This creates a nanoribbon superlattice with a moving line of electrons. These electrons interact quantum mechanically. Depending on the distance between the strips, the hybrid nanoribbon can take on different material properties, such as that of a metal, a semiconductor or a chain of qubits. With the latter, qubits are the basis of quantum computers.
Essentially the spins of adjacent electrons, when positioned correctly, will become entangled. This means that adjusting one affects the others. This is a property that is essential for a quantum computer to operate. When the trapped electrons are separated to the right position, they start to act like small, quantum magnets that can be entangled and become ideal for quantum computing.
The electronic quantum states at junctions of graphene nanoribbons of different widths can transmit a magnetic moment. This makes it possible to process information by the so-called spin or the “direction of rotation” of the electron state.
According to lead researcher Michael Crommie, in conversation with R&D Magazine: “This gives us a new way to control the electronic and magnetic properties of graphene nanoribbons.”
He adds: “We spent years changing the properties of nanoribbons using more conventional methods, but playing with their topology gives us a powerful new way to modify the fundamental properties of nanoribbons that we never suspected existed until now.”
The new development has been published in the journal Nature, with the article headed “Topological band engineering of graphene nanoribbons.”
In related graphene news, scientist Sir Kostya Novoselov has been working with artist Mary Griffiths to create a project called Prospect Planes. This is a video artwork installation based on months of scientific and artistic research and experimentation using graphene as the medium.