Efficient spin excitation via ultrafast damping-like torques in antiferromagnets

Abstract

Damping effects form the core of many emerging concepts for high-speed spintronic applications. Important characteristics such as device switching times and magnetic domain-wall velocities depend critically on the damping rate. While the implications of spin damping for relaxation processes are intensively studied, damping effects during impulsive spin excitations are assumed to be negligible because of the shortness of the excitation process. Herein, we show that, unlike in ferromagnets, ultrafast damping plays a crucial role in antiferromagnets because of their strongly elliptical spin precession. In time-resolved measurements, we find that ultrafast damping results in an immediate spin canting along the short precession axis. The interplay between antiferromagnetic exchange and magnetic anisotropy amplifies this canting by several orders of magnitude towards large-amplitude modulations of the antiferromagnetic order parameter. This leverage effect discloses a highly efficient route towards the ultrafast manipulation of magnetism in antiferromagnetic spintronics.

References in corpus (6)

• Spin Oscillations in Antiferromagnetic NiO Triggered by Circularly Polarized Light
• Tracking the ultrafast motion of an antiferromagnetic order parameter
• Magnetic exchange interaction between rare-earth and Mn ions in multiferroic hexagonal manganites
• Ultrafast Light-driven Simultaneous Excitation of Coherent Terahertz Magnons and Phonons in Multiferroic BiFeO${}_3$
• Asymmetric splitting of an antiferromagnetic resonance via quartic exchange interactions in multiferroic hexagonal HoMnO${}_3$
• Interplay between spin dynamics and crystal field in multiferroic compound HoMnO${}_3$

Cited by in corpus (2)

• Nonlinear terahertz Néel spin-orbit torques in antiferromagnetic Mn${}_2$Au
• Light-induced torque in ferromagnetic metals via orbital angular momentum generated by photon-helicity