Antiferromagnetic magnon pseudospin: Dynamics and diffusive transport

Abstract

We formulate a theoretical description of antiferromagnetic magnons and their transport in terms of an associated pseudospin. The need and strength of this formulation emerges from the antiferromagnetic eigenmodes being formed from superpositions of spin-up and -down magnons, depending on the material anisotropies. Consequently, a description analogous to that of spin-1/2 electrons is demonstrated while accounting for the bosonic nature of the antiferromagnetic eigenmodes. Introducing the concepts of a pseudospin chemical potential together with a pseudofield and relating magnon spin to pseudospin allows a consistent description of diffusive spin transport in antiferromagnetic insulators with any given anisotropies and interactions. Employing the formalism developed, we elucidate the general features of recent non-local spin transport experiments in antiferromagnetic insulators hosting magnons with different polarisations. The pseudospin formalism developed herein is valid for any pair of coupled bosons and is likely to be useful in other systems comprising interacting bosonic modes.

to appear in Physical Review B

References in corpus (8)

• Direct electronic measurement of the spin Hall effect
• Spin Seebeck insulator
• Observation of the Magnon Hall Effect
• Magnon Mediated Electric Current Drag Across a Ferromagnetic Insulator Layer
• Spin Seebeck effect in antiferromagnets and compensated ferrimagnets
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Cited by in corpus (1)

• Role of NiO in the nonlocal spin transport through thin NiO films on Y${}_3$Fe${}_5$O${}_{12}$