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Lasers Pick Atoms Apart

Light could be used to pick apart a substance atom by atom, paving the way for new ways to produce nanoscale diamond devices according to research published in Nature Communications.

“Lasers are known to be very precise at cutting and drilling materials on a small scale – less than the width of a human hair, in fact – but on the atomic scale they have notoriously poor resolution,” says lead researcher A/Prof Richard Mildren of Macquarie University. “If we can harness lasers at higher resolutions, the opportunities at the atomic level are tremendous, especially for future nanoscale devices in data storage, quantum computers, nanosensors and high-power on-chip lasers.”

Current lasers separate materials by super-heating the surface at the focus of the laser beam. While this has been suitable in industries such as car manufacturing, it has severe limitations in the fabrication of nano-devices.

Mildren and co-workers have now discovered that it is possible to remove atoms from a surface using ultraviolet lasers, confining the interaction to the atomic scale and avoiding the heat generation problem that has previously restricted the ability to make precise cuts at the nanoscale.

“So far we have used the technique to demonstrate structures in diamond of size about 20 nm, which is the size of large molecules,” Mildren says. “However, the technique looks highly promising for doing much better, enabling manipulation of surfaces with the ultimate single atom precision, or more than 10,000 times smaller than possible by standard laser machining techniques.”