Flash memory chip built out of single-atom-thick components

The new development could eventually make flash chips like these obsolete.

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Graphene, a single-atom thick sheet of carbon, has become the focus of a lot of research (and a Nobel Prize) because it has some interesting electronic properties: electrons move through the material as if they have no mass. But it's only one of a number of single-atom thick materials that have been discovered, and some of the others have very different properties, acting as semiconductors or insulators.

The discoveries raise the prospect of building more complex electronic devices out of a series of these materials, with each part being only a single atom thick. Now, researchers have used two of these materials—graphene and molybdenum disulfide—and put them together with some more traditional components to make a flash memory device. Although the work is very preliminary, with some of the parts being assembled by hand under a microscope, it shows some excellent properties, like the potential to store more than one bit per device and the ability to retain its state for over a decade.

The basic outline of a flash memory device involves two electrodes that feed current through a semiconductor within the device. When a negative voltage is sent across a device from a control electrode, electrons are able to feed into a reservoir that retains the charge; reversing the voltage allows them to escape. The presence of the electrons in the reservoir can be read out by sending current through the semiconductor.