Graphene may yet make its way into the tiny circuitry thanks to a new property that a team of researchers describe in a paper in Nature Nanotechnology. When placed in a magnetic field, the graphene’s ability to conduct current can be raised or lowered depending on the field’s direction. The property may give scientists a workaround to get even tiny, highly resistant ribbons to conduct current.
We already knew that graphene, which counts among its talents super strength and speed, had unusual electronic properties. One of graphene’s weirdnesses is that when it is cut into very small ribbons—less that five nanometers in size—it is unable to conduct electricity. That’s a potentially useful property for use in nanoelectronics, but only if the behavior could be switched on and off.
Faced with the prospect of electrically apathetic nanoribbons, researchers searched for a workaround. They found that graphene actually has a high magnetoresistance, meaning its ability to conduct current can be altered by putting it in a magnetic field. This works both ways: a field applied in one direction increases resistance and decreases current flow, and another field direction does the opposite.
At room temperature, a magnetic field of 8 tesla reduced a 15 nanometer ribbon’s resistance by 56 percent, and 100 percent at 1.6 Kelvin. The resistance reduction would likely be smaller in the thinner ribbons, where it is needed most. Still, any measure that would allow the ribbons to conduct electricity would be very helpful to anyone trying to use graphene to make their circuits as petite as possible.