{"id":3345,"date":"2011-03-03T07:20:49","date_gmt":"2011-03-03T05:20:49","guid":{"rendered":"http:\/\/localhost\/azgad\/wordpress\/?p=3345"},"modified":"2011-03-03T07:25:54","modified_gmt":"2011-03-03T05:25:54","slug":"vortices-get-organized-exotic-entities-could-lead-to-a-new-approach-to-electronic-memory","status":"publish","type":"post","link":"https:\/\/azgad.com\/?p=3345","title":{"rendered":"Vortices get organized – Exotic entities could lead to a new approach to electronic memory"},"content":{"rendered":"

.
\nA crystal consisting not of atoms but exotic swirling magnetic entities, called skyrmions, has been
\nidentified at near room-temperature by Yoshinori Tokura of the RIKEN Advanced Science Institute,
\nWako, and his colleagues from several other institutes in Japan1. Previous observations of a skyrmion
\ncrystal state, in transition-metal\u2013silicide materials, have been at cryogenic temperatures below 40 kelvin.
\nThe existence of skyrmions at room temperature improves the practicality of harnessing their potential
\nfor use in novel computer memories.
\n.
\n\"\"<\/a>.
\n.
\n
\nFigure 1: In a skyrmion (left) the electron spins, represented as arrows about
\nwhich the electrons are rotating, are arranged such they map onto the surface of
\na sphere (right). <\/strong>
\n.
\n.
\n.<\/p>\n

Skyrmions are formed on some surfaces when the spins of the electrons\u2014think of an arrow about
\nwhich each electron rotates\u2014collectively arrange such that they wrap around the surface of a sphere
\n(Fig. 1). This pattern spirals in such a way that the spins on the outside point up whereas those at the
\ncore point down. This collection of spins can display many properties associated with a single particle.
\n\u201cA skyrmion crystal is the periodic array of these particle-like entities,\u201d explains Tokura.
\n.
\nEarlier neutron-scattering experiments by other researchers identified this unusual effect in both iron\u2013cobalt
\nsilicide and manganese silicide. Tokura and his team, however, investigated skyrmions in iron germanium.
\nThis alloy has the same cubic atomic crystal structure as iron\u2013cobalt silicide and manganese silicide\u2014the two
\nmaterials in which skyrmions have been observed at low temperatures; but it remains in the necessary magnetic
\nstructure up to a much higher temperature.
\n.
\nUsing a transmission electron microscope, the researchers probed the magnetization on the surface of polished
\nlayers of the iron\u2013germanium alloy. They found tell-tale signs of skyrmions at temperatures up to 260 kelvin,
\nparticularly when they applied a small magnetic field perpendicularly to the surface.
\n.
\nThis material also provides an excellent opportunity to investigate the stability of the skyrmion crystal, the team notes.
\nPrevious studies focused on very thin layers of material. Tokura and his team investigated the influence of film thickness
\nand found that for thicknesses greater than the distance between skyrmions, about 75 nanometers in this case, the
\nskyrmion crystal state is suppressed and a more conventional ferromagnetic phase starts to dominate.
\n.
\nSkyrmions could play an important role in the development of spintronics\u2014using electron spin to carry information in the same
\nway that electron charge is used in conventional electronics. \u201cSkyrmion crystals could also be applied in memory and logic devices,
\n\u201d says Tokura. The advantage over conventional systems is that control is achieved using electric, rather than magnetic fields, which
\nis known to be more efficient.<\/p>\n","protected":false},"excerpt":{"rendered":"

. A crystal consisting not of atoms but exotic swirling magnetic entities, called skyrmions, has been identified at near room-temperature by Yoshinori Tokura of the RIKEN Advanced Science Institute, Wako, and his colleagues from several other institutes in Japan1. Previous observations of a skyrmion crystal state, in transition-metal\u2013silicide materials, have been at cryogenic temperatures below … <\/p>\n

\u05d4\u05de\u05e9\u05d9\u05db\u05d5 \u05d1\u05e7\u05e8\u05d9\u05d0\u05d4<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[10],"tags":[513,49],"class_list":["post-3345","post","type-post","status-publish","format-standard","hentry","category-10","tag-513","tag-49","nodate","item-wrap"],"_links":{"self":[{"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts\/3345","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=3345"}],"version-history":[{"count":4,"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts\/3345\/revisions"}],"predecessor-version":[{"id":3351,"href":"https:\/\/azgad.com\/index.php?rest_route=\/wp\/v2\/posts\/3345\/revisions\/3351"}],"wp:attachment":[{"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=3345"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=3345"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/azgad.com\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=3345"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}