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Evidence for stable room-temperature skyrmions

Date:
July 2, 2015
Source:
RIKEN
Summary:
Researchers have identified a class of materials that displays clear evidence for stable skyrmions at room temperature and above, paving the way for the development of useful spintronics devices.
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Magnetic skyrmions.
Credit: Image courtesy of RIKEN

In research published in Nature Communications, researchers from the RIKEN Center for Emergent Matter Science in Japan, along with collaborators in Europe and Japan, have identified a class of materials that displays clear evidence for stable skyrmions at room temperature and above, paving the way for the development of useful spintronics devices.

Magnetic skyrmions are tiny, nanometer-sized magnetic-spin vortices that emerge on the surface of magnetic materials. Because they are so small, they could potentially be used as extremely dense memory devices, with the presence or absence of skyrmions, or the direction of spin, being used to denote bits in computer calculations. Achieving this could lead to the advent of a new class of low-power-consumption devices dubbed "spintronics," as well as ultra-low consumption, high-density magnetic memory.

However, skyrmions are not always easy to use. Though they occur ubiquitously in magnets, in a diverse range of circumstances, they are not always easy to control. The ultimate dream of researchers has been to create stable skyrmions -- which do not decay -- in a set chirality, so that their chirality can be manipulated to represents data for storage devices

Skyrmions emerging from a process called the Dzyaloshinskii-Moriya interaction have been considered to be particularly promising, as they are small (under 150 nanometers) and have a fixed direction of spin, so that they could host a large number of stable skyrmions which could be manipulated by electrical currents, and hence could be used to create high-density storage. Such stable skyrmions have been found in certain crystal structures, but in the materials studied so far, such as Cu2OSeO3, the skyrmions emerge most strongly in low temperatures, requiring low-temperature manipulation.

For the present study, the scientists decided to look at a type of magnetic material made up of cobalt, zinc, and manganese, whose structure seemed likely to host stable skyrmions. Using a variety of techniques, they were able to show indeed that when a magnetic field was applied, the material showed the clear presence of skyrmion crystals in both a bulk shape and when shaped into a thin plate. These skyrmions were both stable and chiral -- meaning that they spun in a set direction -- so that they could be manipulated to encode information depending on the chirality.

According to Yusuke Tokunaga of CEMS, who performed the work, "We are quite excited about these results, as they may answer the long-held expectation that we can find skyrmion hosting systems in a variety of new materials. In addition, the fact that we have shown that skyrmions can be stabilized at room temperature and above opens the road to looking for ways to integrate skyrmions into spintronics devices without complicated cooling systems.

The research was done by CEMS scientists in collaboration with scientists from the Paul Scherrer Institut and Ecole Polytechnique Federale de Lausanne in Switzerland and the University of Tokyo in Japan.


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Materials provided by RIKEN. Note: Content may be edited for style and length.


Journal Reference:

  1. Y. Tokunaga, X. Z. Yu, J. S. White, H. M. Rønnow, D. Morikawa, Y. Taguchi, Y. Tokura. A new class of chiral materials hosting magnetic skyrmions beyond room temperature. Nature Communications, 2015; 6: 7638 DOI: 10.1038/ncomms8638

Cite This Page:

RIKEN. "Evidence for stable room-temperature skyrmions." ScienceDaily. ScienceDaily, 2 July 2015. <www.sciencedaily.com/releases/2015/07/150702073734.htm>.
RIKEN. (2015, July 2). Evidence for stable room-temperature skyrmions. ScienceDaily. Retrieved May 23, 2017 from www.sciencedaily.com/releases/2015/07/150702073734.htm
RIKEN. "Evidence for stable room-temperature skyrmions." ScienceDaily. www.sciencedaily.com/releases/2015/07/150702073734.htm (accessed May 23, 2017).

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