  We propose a time-delay oscillator with Mackey-Glass nonlinearity based on a
pinned magnetic domain wall in a thin film nanostrip. Through spin transfer
torques, electric currents applied along the strip cause the domain wall to
deform and displace away from a geometrical pinning site, which can be
converted into a nonlinear transfer function through a suitable choice of a
readout. This readout serves as a delay signal, which is subsequently fed back
into the applied current with amplification. With micromagnetics simulations,
we study the role of the readout position, time delay, and feedback gain on the
dynamics of this domain wall. In particular, we highlight regimes in which
self-sustained oscillations and complex transients are possible.

Mesoscale and Nanoscale Physics;Applied Physics