  Magnetic droplet solitons are non-linear dynamical modes that can be excited
in a thin film with perpendicular magnetic anisotropy with a
spin-transfer-torque. Although droplet solitons have been proved to be stable
with a hysteretic response to applied currents and magnetic fields at low
temperature, measurements at room temperature indicate less stability and
reduced hysteresis width. Here, we report evidence of droplet soliton drift
instabilities, leading to drift resonances, at room temperature that explains
their lower stability. Micromagnetic simulations show that the drift
instability is produced by an effective field asymmetry in the nanocontact
region that can have different origins.
