Nanometric magnetic skyrmions – a kind of "mini vortex of spins" – hold great promise for the storage and processing of information due to their nanoscale size, stability, and the low energy cost required in handling them.

Originally predicted in the 1980s, magnetic skyrmions consist of a localized magnetization "texture" that was only observed for the first time in 2009. In 2012, two research teams demonstrated that they can be manipulated by very weak electrical currents, paving the way for their use as information carriers. However, their use is limited by the need for very low temperatures (-240°C) and the application of a magnetic field.

In 2016, researchers from the Irig demonstrated the existence of magnetic skyrmions at room temperature, in a very thin layer of cobalt only a few atoms thick, embedded between a layer of platinum and a layer of magnesium oxide.

They have now taken a further step towards their applicability by stabilizing magnetic skyrmions that are five times smaller than before (as much as 30 nm), without the use of a magnetic field.

To achieve this, they combined an antiferromagnetic layer with the ultra-thin ferromagnetic layer carrying the skyrmions. They are already familiar with this type of stack, as it is used in MRAM magnetic memories. In order to observe these very small skyrmions, they had to use an innovative technique: NV (Nitrogen Vacancy) center magnetic microscopy, which has already been mastered by the University of Montpellier.