Magnetic anisotropy-controlled vortex nano-oscillator for neuromorphic computing

Chiral magnetic vortex has shown great potential for high-density magnetic
storage, modern telecommunication and computation devices, thanks to its
topological stability and rich dynamic behaviours. Particularly, the
synchronization of magnetic vortex nano-oscillators leads to the emergence
of fascinating collective phenomena used for microwave generator and
neuromorphic computing. In this work, by means of micromagnetic
simulations, we create stable chiral magnetic vortices by exploiting the chiral
coupling principle and study the gyrotropic motion of the vortex core under
spin-transfer torques. The gyrotropic oscillation frequency can be tuned by
injecting spin-polarised current as well as the change of the magnetic
anisotropy in the vortex area, resulting from the modification of the vortex
confine potential and the size of the vortex core. Two vortex nano-oscillators
can be synchronized wherein the synchronization state can be modulated by
the spin-polarised current and the magnetic anisotropy. Moreover, we
demonstrate that the magnetic anisotropy can modify the synchronization
patterns when integrating six vortices into an oscillator network, making it
potentially serve as an oscillator-based neural network. Our work provides a
new route to constructing a flexible oscillator network for neuromorphic
computing hardware.