Abstract---Due to long-range dipolar coupling, a thin nanomagnet of adequate size can support a single
vortex ground state. Placing one or more holes in the magnet, on which a vortex will be
pinned energetically, control over the vortex position and circulation can be obtained,
which can lead to designs for switching or memory devices. The REU project would involve
programming energy minimization and Monte Carlo simulations for this kind of model.
See the short introductory presentation to this topic.
Image at right: A strong current points into the page through the hole, causing reversal
of the circulation of the vortex pinned on the hole, by the production of both a positive and
negative vortex that exit the system! The initial circulation was counterclockwise. The currrent
forces clockwsie circulation to be lower energy. The spin configuration was produced by a
Monte Carlo simulation. ------>