Rahm, M. and Stahl, Joachim and Wegscheider, Werner and Weiss, Dieter
Multistable switching due to magnetic vortices pinned at artificial pinning sites.
Applied Physics Letters 85 (9), pp. 1553-1555.
Magnetic vortices form the ground state in micron and submicron ferromagnetic disks. By inserting artificial defects (antidots) into a submicron ferromagnetic disk, magnetic vortices can be pinned controllably thus enabling a different way for magnetic switching. We show that by inserting n antidots into a disk magnetization reversal takes place via n-1 jumps of the vortex core between neighboring antidots. This cannot only be used to establish stable two-state switching for n = 2, but also to realize a multilevel remanent state with low switching fields.