Collaborative Proposal: Physics of Ferromagnetic Nanostructures in a Circular Field

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****Technical Abstract****This collaborative project between Mount Holyoke College and the University of Massachusetts, Amherst, explores magnetic states in ferromagnetic nanostructures by applying a local circular field generated by passing current through the tip of an atomic force microscope, as well as applying current pulses through the AFM tip or fabricated leads on the sample. These techniques will allow for separate control over the vortex and vortex core of magnetic disks, as well as manipulation of individual domain walls (DWs) in wires to investigate the physics of different types of DWs and interactions between them. Sufficiently thin ferromagnetic nanorings are predicted to have unique states that consist of pairs of 360 degrees domain walls (DWs) when switching between vortex states in an applied circular field. Understanding DWs and circular nano-structures will inform the next generation of data storage devices. This work will involve the undergraduate women at Mount Holyoke College, as well as post-docs and graduate students, fostering frequent interaction between the two institutions. Furthermore, curricular material on magnetism will be developed for established programs with K12 teachers and the nearby Springfield Technical Community College, and a local Science Café will be created, bringing experts in science and technology to speak with the general public in an informal setting.****Non-Technical Abstract****Computer hard drives presently store information in binary bits of "1" and "0" that are encoded in what are effectively little bar magnets with either the north or south pole pointing up. There are a variety of proposals for improved data storage devices, including circular nanostructures that could store the "1" and "0" in a unique clockwise or counterclockwise "vortex" state, and devices that store information in the domain walls that form between oppositely magnetized sections of a wire. Traditionally, magnetization has been studied using uniform external fields. This collaborative project between Mount Holyoke College (MHC) and the University of Massachusetts, Amherst (UMass), uses a recently developed technique to investigate magnetic states by generating a local non-uniform, circular magnetic field by precisely positioning a tiny wire and passing a current through the wire that creates the magnetic field. This work will involve the undergraduate women at Mount Holyoke College, as well as post-docs and graduate students, fostering frequent interaction between the two institutions. Curricular material on magnetism will be developed for established programs with K12 teachers and the nearby Springfield Technical Community College and a Science Café will be created, bringing experts in science and technology to speak with the general public in an informal setting.