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Scientists are endeavoring to create novel type of electronic devices based on graphene's ballistic property. The property states that graphene has the unique ability to smoothly carry tens or hundreds of electrons along the edges of the material without causing any resistance at room temperature.
Graphene nanoribbons act like optical wave guides to transfer electrons and the electrical resistance of which changes in discrete steps following quantum mechanical principles. But, this does not happens with other conductors like copper, the resistance of which increases as electrons travels along the length of the material.
After analyzing ballistic properties of graphene in cylindrical carbon nanotubes, researchers found 10 times increase in conductance of graphene. They measured ballistic properties in 40-nanometer wide graphene nanoribbons grown on the edges of three dimensional structures embedded into silicon carbide wafers.
For the past 10 years, researchers have been trying their level best to create graphene based devices, but were failing to attain desired electronic band-gap needed for such devices to operate.
Walt de Heer, a Regent's professor in the School of Physics at the Georgia Institute of Technology, said that resistance of any material does not depend on temperature, but on amount of current flowing through it.
He cited an example and said that touching nanoribbons of graphene with one probe increases resistance by two times and increases with increase in number of probes.
In the novel research, researchers firstly deposited layer of nanoribbons on silicon carbon wafers and then used microelectronics fabrication techniques to scratch patterns on them. Later on, the silicon wafers were heated to about 1000 degrees Celsius, resulting in extraction of silicon material along the edges. Thus, allowing smooth transfer of electrons through the material.
Manufacturing of graphene based devices was started for first time by Georgia Tech researchers in 2001 and they filed for patent in 2003.
