Etch-A-Sketch inspires single electron transistor

Researchers at the University of Pittsburgh, HP Labs and UW Madison, have built a single electron transistor that will operate with the addition of just one or two more electrons.

The new device, hailed as a potential building block for ever smaller and denser memory devices, and even quantum computers, was created with an atomic scale "Etch-a-Sketch" developed by Prof. Jeremy Levy back in 2008.

This nifty little piece of kit uses the probe of an atomic force microscope to etch nano-metre scale device on the interface of a crystal of strontium titanate and a 1.2 nanometer thick layer of lanthanum aluminate. Where the probe passes, it positively charges the surface layer of the material, attracting electrons in the layer beneath.

From the press release: "The SketchSET—which is the first single-electron transistor made entirely of oxide-based materials—consists of an island formation that can house up to two electrons. The number of electrons on the island—which can be only zero, one, or two—results in distinct conductive properties. Wires extending from the transistor carry additional electrons across the island."

The transistor also turns out to be ferroelectric, which is useful because it means it can be either on Single electron transistoror off when the power is disconnected, making it potentially useful as a memory component as well.

The work is published in the April 17 edition of the journal Nature Nanotechnology.