Spin-transfer torque induced spin waves in antiferromagnetic insulators

TL;DR

This paper investigates how spin currents can excite spin waves in antiferromagnetic insulators, revealing the influence of interface type, spin current polarization, and surface anisotropy on the excitation process.

Contribution

It demonstrates that spin-transfer torque can induce spin waves in antiferromagnetic insulators and highlights the role of surface anisotropy in enhancing these excitations.

Findings

Spin currents can excite spin waves in antiferromagnetic insulators.

The chirality of spin waves depends on the spin current polarization.

Surface anisotropy significantly increases excitation accessibility.

Abstract

We explore the possibility of exciting spin waves in insulating antiferromagnetic films by injecting spin current at the surface. We analyze both magnetically compensated and uncompensated interfaces. We find that the spin current induced spin-transfer torque can excite spin waves in insulating antiferromagnetic materials and that the chirality of the excited spin wave is determined by the polarization of the injected spin current. Furthermore, the presence of magnetic surface anisotropy can greatly increase the accessibility of these excitations.