Magnon drag in a metal–insulating antiferromagnet bilayer

Abstract

We study a bilayer structure consisting of an antiferromagnetic insulator and a normal metal. An electron current is driven in the normal metal with direction parallel to the interface between the materials. Due to interfacial exchange coupling between the localized spins in the antiferromagnet and the itinerant electrons in the normal metal, a magnon current can then be induced in the antiferromagnet. Using an uncompensated antiferromagnetic interface, creating an asymmetry in the interfacial coupling to the two degenerate magnon modes, we find that it is possible to generate a magnon spin current. The magnon spin current can be enhanced by increasing the temperature or by spin-splitting the magnon modes.

Magnon drag in a metal–insulating antiferromagnet bilayer