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Data Storage Concept: Flaws with Benefits

Material defect improves sensitivity

Jülich, 31 March 2020. In the production of nanoelectronic components, material defects are usually unwelcome as they can impair desired behaviour. However, new computer simulations by a team of physicists at Forschungszentrum Jülich show that such defects can also be useful. According to their studies, material defects – introduced using a targeted approach – could improve the performance of a certain class of data storage devices.

So-called “race track memory” chips are a concept for future high-performance and energy-saving data memory chips. They could one day store data in the form of tiny magnetic vortices known as skyrmions. The vortices move within the memory chip and are read out at sensor sites by measuring the electrical resistance. As early as 2015, a team led by Prof. Samir Lounis of the Peter Grünberg Institute and the Institute for Advanced Simulation, who is also involved in the current study, had developed the concept and calculated that it should be possible to increase the integration density of data by a factor of 500 at the same speeds.

Skyrmions occur at the surface or interface of thin metal films and, being just a few nanometres in size, are among the smallest known stable magnetic forms. Using computer simulations, the researchers led by Samir Lounis have now discovered that individual atomic defects in the metal films can lead to significantly stronger signals when the skyrmions are read out. “You can imagine this as having the same effect as a magnifying glass, where the skyrmions are more easily identified,” explains Samir Lounis enthusiastically. “This is also beneficial for complicated multi-layer structures, because signals from skyrmions can be read out even in deeper layers.” This would enable the further miniaturization of memory chips.

According to the researchers, the effect could be exploited by introducing the material defects specifically at the positions in the memory chip where the skyrmions are read out. As soon as a skyrmion travels into the vicinity of a defect, this changes the electronic properties of the defect. A sensor that measures the electrical resistance at this point registers a change in the electrical resistance. The researchers are now planning further studies on the effects of more complex material defects and whether detection is also possible by optical means instead of electrical.

Datenspeicherkonzept: Vorteilhafter FehlerIn the concept of so-called “race track memory” technology, a skyrmion (vortices made of coloured arrows) is supposed to encode a “zero”, ferromagnetic areas (blue arrows) a “one”. The spin-mixing magnetoresistance (XMR) effect and its variants, intensified by material defects, could make it possible to read out data electrically. In this concept, the vortices move through the memory chip and are read out at sensor sites (brown plates).
Copyright: Quelle: Forschungszentrum Jülich

Originalpublikation: Defect-implantation for the all-electrical detection of non-collinear spin-textures; Imara Lima Fernandes, Mohammed Bouhassoune, Samir Lounis; Nature Communications 2020, DOI: 10.1038/s41467-020-15379-6

Further information:

Press release from 16.10.2015: New Magnetic Effect Detects Magnetic Nano-Vortices

Scientific bulletin from 22.10.2018: Towards IT of the Future: Interactions of Skyrmions Better Understood

Work Group: Functional Nanoscale Structure Probe and Simulation Laboratory (Funsilab) at Forschungszentrum Jülich: www.fz-juelich.de/pgi/Group-Lounis 

Contact:

Prof. Dr. Samir Lounis
Quantum Theory of Materials (PGI-1/IAS-1)
Forschungszentrum Jülich
Tel. +49 2461 61-4068
E-Mail: s.lounis@fz-juelich.de

Presse contact:

Angela Wenzik
Science Journalist
Forschungszentrum Jülich
Tel. +49 2461 61-6048
E-Mail: a.wenzik@fz-juelich.de