Néel-Vector Switching and THz Spin-Wave Excitation in Mn${}_2$Au due to Femtosecond Spin-Transfer Torques

Abstract

Efficient and fast manipulation of antiferromagnets has to date remained a challenging task, hindering their application in spintronic devices. For ultrafast operation of such devices, it is highly desirable to be able to control the antiferromagnetic order within picoseconds - a timescale that is difficult to achieve with electrical circuits. Here, we demonstrate that bursts of spin-polarized hot-electron currents emerging due to laser-induced ultrafast demagnetization are able to efficiently excite spin dynamics in antiferromagnetic Mn${}_2$Au by exerting a spin-transfer torque on femtosecond timescales. We combine quantitative superdiffusive transport and atomistic spin-model calculations to describe a spin-valve-type trilayer consisting of Fe$|$Cu$|$Mn${}_2$Au. Our results demonstrate that femtosecond spin-transfer torques can switch the Mn${}_2$Au layer within a few picoseconds. In addition, we find that spin waves with high frequencies up to several THz can be excited in Mn${}_2$Au.

References in corpus (4)

• Super-Diffusive Spin-Transport as a Mechanism of Ultrafast Demagnetization
• Writing and Reading antiferromagnetic Mn${}_2$Au: Néel spin-orbit torques and large anisotropic magnetoresistance
• Subterahertz spin pumping from an insulating antiferromagnet
• Ultrafast Switching of Antiferromagnets via Spin-transfer Torque

Cited by in corpus (1)

• Fast reversal of Néel vectors in antiferromagnets via domain-wall motion driven by vertically injected spin currents