Staggered Dynamics in Antiferromagnets by Collective Coordinates

Erlend G. Tveten, Alireza Qaiumzadeh, O. A. Tretiakov, and Arne Brataas

Phys. Rev. Lett. 110, 127208 – Published 21 March 2013

Abstract

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.

Received 1 October 2012

DOI:https://doi.org/10.1103/PhysRevLett.110.127208

Authors & Affiliations

Erlend G. Tveten¹, Alireza Qaiumzadeh¹, O. A. Tretiakov^2,3, and Arne Brataas¹

¹Department of Physics, Norwegian University of Science and Technology, NO-7491 Trondheim, Norway
²Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan
³Department of Physics and Astronomy, Texas A&M University, College Station, Texas 77843-4242, USA