Alternating Motion of Single-Domain Walls in Uniaxial Magnetic Wire

Fe-Si-B microwires with strong uniaxial anisotropy reverse magnetization under homeogeneous driving magnetic field, H
_dr
, by the nucleation at one end and propagation of a single standard domain wall, DW
_st
, resulting in a giant Barkhausen jump between two stable remanent states with opposite magnetization. Under the additional presence of local field, H
_loc
, a local reverse domain is nucleated, generating a pair of head-to-head and tail-to-tail injected walls, DW
_inj
, that propagate in opposite directions. We performed designed experiments to control the motion of the DW
_st
and DW
_inj
under the action of both fields. The amplitude and frequency of square-shaped in-phase H
_dr
and H
_loc
ac fields are tuned to achieve controlled motion of the DW
_inj
domain wall. By properly selecting the amplitude of H
_dr
and H
_loc
ac fields (i.e., double or multiple frequencies), we experimentally confirm the DW
_inj
alternating motion between stable local positions/magnetic states, where H
_loc
plays the role of a magnetic valve and H
_dr
is the driving field.