Mathematical & Physical Sciences


A single atom magnet

Publication date: Dec 9, 2013 12:09:29 PM

Single atom magnet. Picture: Alfaro Cuevas (alfarocuevas.blogspot.com)

Quantum phenomena, things which occur on scales of atoms or molecules, are impossible to photograph. The problem isn't that microscopes aren't powerful enough – it's that the wavelength of light is too long to resolve any detail at those scales.

Scientists use tools such as electron microscopes, which can map objects and surfaces at far smaller scales, and can even pinpoint individual atoms. But the pictures that come from these are hard for non–specialists to interpret: they are like an Ordnance Survey map compared to an aerial photograph of the same scene.

The picture above is an attempt to get around this: drawn by artist Alfaro Cuevas, working with a team of scientists at UCL Quantum, the artwork illustrates the magnetic properties of individual atoms, the subject of a study published today in the journal Nature Nanotechnology.

When directly on a metal surface, the magnetism (black arrows) of a single cobalt atom (orange) is screened by strong interactions with the surrounding metallic sea (blue). By moving these atoms towards the centre of an island of thin insulator material (white), we can gradually decrease that strength of that interaction, which results in a remarkable enhancement of the magnetic anisotropy (the way in which the way in which magnetic poles lie along a particular direction, rather than being randomly distributed).

Credit: Alfaro Cuevas (alfarocuevas.blogspot.com), CC–BY–ND


High resolution image

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