A researchers team at RWTH Aachen and the National Institute of Materials Science in Japan work with bilayer graphene, which can be tuned to be a semiconductor. A voltage applied to specific regions of a bilayer graphene flake can switch those regions to behave as insulators, electrostatically defining a quantum dot that has no edge states nearby.
Although this level of control has been demonstrated in single quantum dots, this is the first demonstration in graphene double quantum dots, which are particularly useful as spin qubits.
These results could prove key to future implementations of quantum computing based on graphene.
This first demonstration of graphene double quantum dots in which it is possible to control the number of electrons down to zero has been reported in Nano Letters. (Phys.org)