Quantum Effect Successfully Tuned in Bilayer GrapheneCategory: Science & Technology
Posted: July 8, 2014 02:02PM
Graphene is a wonder material for many reasons, including its fantastic electrical properties and great strength. It is also special for being a high quality crystal, which can have implications for quantum mechanics. Researchers at Columbia University have recently discovered a means to tune a quantum mechanical phenomenon in bilayer graphene, which could enable it to be used in quantum computers.
The fractional quantum Hall effect involves many electrons being made to act like a single system when confined to a thin sheet and exposed to a large magnetic field. As graphene is an atom-thick sheet of carbon, it is a perfect fit for studying the effect, and it has been. This new research looks to bilayer graphene, which has some differing behaviors from single-layer graphene, such as developing a bandgap when exposed to a strong magnetic field, disrupting the electrodes ability to tune the charge density. It took some time, but the Columbia researchers eventually found a new design for the graphene system that allowed them to isolate the electrodes from the needed magnetic fields.
Now with the ability to control the charge density on the separate graphene sheets, the researchers can create the fractional quantum Hall effect in bilayer graphene, which could allow for non-abelian states to be created. These states could be used for quantum computation, but not before the researchers better understand what is happening to the electrons, as the system is so complex they are not entirely sure what is occurring.