Antiferromagnetic domain wall motion induced by spin waves.

Spin waves in antiferromagnets are linearly or circularly polarized. Depending on the polarization, traversing spin waves alter the staggered field in a qualitatively different way. We calculate the drift velocity of a moving domain wall as a result of spin wave-mediated forces and show that the domain wall moves in opposite directions for linearly and circularly polarized waves. The analytical results agree with micromagnetic simulations of an antiferromagnetic domain wall driven by a localized, alternating magnetic field.

Staggered dynamics in antiferromagnets by collective coordinates.

Antiferromagnets can be used to store and manipulate spin information, but the coupled dynamics of the staggered field and the magnetization are very complex. We present a theory which is conceptually much simpler and which uses collective coordinates to describe staggered field dynamics in antiferromagnetic textures. The theory includes effects from dissipation, external magnetic fields, as well as reactive and dissipative current-induced torques. We conclude that, at low frequencies and amplitudes, currents induce collective motion by means of dissipative rather than reactive torques. The dynamics of a one-dimensional domain wall, pinned at 90° at its ends, are described as a driven harmonic oscillator with a natural frequency inversely proportional to the length of the texture.