  Magnetic vortices in soft ferromagnetic nano-disks have been extensively
studied for at least several decades both for their fundamental (as a "live"
macroscopic realization of a field theory model of an elementary particle) as
well as applied value for high-speed high-density power-independent information
storage. Here it is shown that there is another stable vortex state with large
thickness-dependent core profile in nano-scale ferromagnetic disks of several
exchange lengths in size. Its energy is computed numerically (in the framework
of Magnetism@home distributed computing project) and its stability is studied
analytically, which allows to plot it on magnetic phase diagram. In cylinders
of certain geometries large vortices exist on par with classical ones, while
being separated by an energy barrier, controllable by tuning the geometry and
material of ferromagnetic disk. They can be an excellent candidate for magnetic
information storage not only because the resulting disk sizes are among the
smallest, able to support magnetic vortices, but also because it is the closest
to the classical vortex state of all other known metastable states of magnetic
nano-cylinder. It means that memory, based on switching between these two types
of magnetic vortices, may, potentially, achieve the highest possible rate of
switching.
