Terahertz emission in the ferromagnetic-antiferromagnetic structure

Abstract

Current flow in the structure consisting of a hard-magnetic ferromagnetic rod (hardened steel) with a diameter of up to 100 μm that contacts a thin (10–100 nm) ferromagnetic (FeMn) film is studied at room temperature. Effective magnetization is induced in the FeMn film in the presence of the spin-polarized current in spite of the absence of the intrinsic magnetization. The terahertz radiation that is detected in this work is caused by the precession of the induced magnetization. The emission is interpreted using the recent theoretical predictions on the effect of the sd exchange on the lattice dynamics of antiferromagnetic layer.