  Nanoscale magnetic domains with controllable configurations could be used for
classical and quantum applications, where the switching of magnetization
configurations is an essential operation for information processing. Here, we
report that the magnetic domain reorientation in a notched ferromagnetic
nanotrack can be realized and effectively controlled by applying uniform
magnetic field pulses in a fixed in-plane direction perpendicular to the
nanotrack. Our micromagnetic simulation results show that the configurations of
magnetic domains in the notched nanotrack can be switched between a
head-to-head state and a tail-to-tail state in a reversible manner driven by
magnetic field pulses, while it is unnecessary to reverse the direction of the
magnetic field. Such a unique magnetic domain reorientation dynamics is found
to depend on magnetic parameters and nanotrack geometries. The reorientation
dynamics of magnetic domains also depends on the strength and length of the
applied magnetic field pulse. In addition, we point out that the notches at the
center of the nanotrack play an important role for the stabilization of the
head-to-head and tail-to-tail states during the magnetic domain reorientation.
We also qualitatively explain the field-induced reorientation phenomenon with a
simplified two-dimensional macrospin model. Our results may make it possible to
build spintronic devices driven by a fixed magnetic field. Our findings may
also motivate future studies to investigate the classical and quantum
applications based on nanoscale magnetic domains.
