Researchers from the National Institute of Standards and Technology (NIST) and the University of Maryland have shown that subjecting graphene to mechanical strain can mimic the effects of magnetic fields and create a quantum dot.
The researchers fabricated graphene "drumheads" by suspending graphene over shallow holes in a substrate of silicon dioxide. When using unique scanning probe microscope designed and built at NIST, they noticed that the graphene rose up to meet the tip of the microscopeâ a result of the van der Waals force, a weak electrical force that creates attraction between objects that are very close to each other. The strain in the "drumhead" could be tuned by using the conducting plate upon which the graphene and substrate were mounted to create a countervailing attraction and pull the drumhead down. This changed the material's electrical properties.
When they pulled the graphene membrane into the tent-like shape, the region at the apex acted just like a quantum dot. This isn't the first time graphene is used to fabricate Quantum Dots.