Researchers at the National University of Singapore have made computer memory devices using graphene, a flat sheet of hexagonally arranged carbon atoms capable of transporting electrons at high speeds. The researchers' graphene memory could be the first step toward memory that is far denser and faster than the magnetic memory used in modern hard drives. National University of Singapore professor Barbaros Ozyilmaz led the researchers in the construction of prototype graphene memory devices.
Ozyilmaz says graphene is going to change the electronics industry, and all that was missing was a way to use graphene as a memory device. The key to making memory is having a material that can be in two different states to represent two different bits, 1s and 0s. Hard drives also need to be nonvolatile, or capable of storing information without a constant power supply. Ozyilmaz and his colleagues developed an easy way of making graphene hold two different levels of conductivity, or resistance. Switching between the levels requires applying and removing an electric field. The researchers deposited a thin layer of ferroelectric material, which has an intrinsic electric field that can be changed by applying a voltage change and helps sustain conductivity. By changing the polarization of the ferroelectric, the conductivity of the graphene is also changed. Graphene memory could be read 30 times faster than magnetic memory because electrons move through graphene so quickly, and memory also could be denser, providing more storage in a smaller space.
From Technology Review
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