  Magnetic vortex dynamics in lithographically prepared nanodots is currently a
subject of intensive research, particularly after recent demonstration that the
vortex polarity can be controlled by in-plane magnetic field. This has
stimulated the proposals of non-volatile vortex magnetic random access
memories. In this work, we demonstrate that triangular nanodots offer a real
alternative where vortex chirality, in addition to polarity, can be controlled.
In the static regime, we show that vortex chirality can be tailored by applying
in-plane magnetic field, which is experimentally imaged by means of
Variable-Field Magnetic Force Microscopy. In addition, the polarity can be also
controlled by applying a suitable out-of-plane magnetic field component. The
experiment and simulations show that to control the vortex polarity, the
out-of-plane field component, in this particular case, should be higher than
the in-plane nucleation field. Micromagnetic simulations in the dynamical
regime show that the magnetic vortex polarity can be changed with
short-duration magnetic field pulses, while longer pulses change the vortex
chirality.
