EAPSI: Detection and Manipulation of the Exotic Magnetic Structures known as Skyrmions in Nanowires for Next Generation Information Storage Applications

Stolt Matthew J, Madison WI

Investigators

Abstract

Improvement of high density information storage systems, such as magnetic hard drives, is imperative for the continued success of computers and the internet. Unlike computer processing units (CPUs) which still have a fair amount of room for traditional improvement, information storage systems, like magnetic hard drives, are approaching their limits and will need new materials to break through these limits. One new approach that has garnered much attention in the physics community is the use of exotic magnetic domains known as skyrmions which are analogous to magnetic bubbles in which information can be written and stored. These ?magnetic bubbles? can be smaller than the magnetic domains used currently in magnetic hard drives which can allow for more information to be stored in a smaller area. The PI will collaborate with Professor Minglian Tian at the Chinese Academy of Sciences who is a known expert in the field of nanoscale magnetism for electronics applications which includes skyrmions. Along with Tian's expertise, his lab has a number of instruments that allow for the study of skyrmions and their electronic applications in single nanowire device prototypes. Novel nanowires of FeGe and Mn1-xFexSi which are known to host skyrmions have been synthesized via a chemical vapor deposition route. Single nanowire devices of each type of nanowire will be made in Prof. Tian?s lab using their state of the art Focus Ion beam (FIB). The FIB will write Pt electrical leads to an isolated wire picked by a micromanipulator. The stability of the skyrmion phase in the nanowires will then be mapped using magnetoresistance and Hall effect measurements carried out in the group?s own physical properties measurement system (PPMS). The stability of the skyrmions is expected to be increased compared to large single crystals due the spatial confinement of the skyrmions in the nanowire host. Once the skyrmion phase diagram has been mapped for each system, new electrical detection methods will be studied. If the project is successful, two new nanowire systems will have had their skyrmion properties thoroughly studied, and more importantly a novel and facile way to detect single skyrmions will be developed. Being able to detect single skyrmions would be a large step toward utilizing skyrmions in next generation electronic information storage systems. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Ministry of Science and Technology of China.