Probing ultrafast spin dynamics in the antiferromagnetic multiferroic HoMnO${}_3$ through a magnon resonance

Abstract

We demonstrate a new approach for directly measuring the ultrafast energy transfer between elec- trons and magnons, enabling us to track spin dynamics in an antiferromagnet (AFM). In multiferroic HoMnO3, optical photoexcitation creates hot electrons, after which changes in the spin order are probed with a THz pulse tuned to a magnon resonance. This reveals a photoinduced transparency, which builds up over several picoseconds as the spins heat up due to energy transfer from hot elec- trons via phonons. This spin-lattice thermalization time is ?10 times faster than that of typical ferromagnetic (FM) manganites. We qualitatively explain the fundamental differences in spin-lattice thermalization between FM and AFM systems and apply a Boltzmann equation model for treating AFMs. Our work gives new insight into spin-lattice thermalization in AFMs and demonstrates a new approach for directly monitoring the ultrafast dynamics of spin order in these systems.

References in corpus (5)

• Spin Oscillations in Antiferromagnetic NiO Triggered by Circularly Polarized Light
• Ultrafast energy and momentum resolved dynamics of magnetic correlations in photo-doped Mott insulator Sr${}_2$IrO${}_4$
• Ultrafast carrier dynamics and radiative recombination in multiferroic BiFeO${}_3$
• Magnetic exchange interaction between rare-earth and Mn ions in multiferroic hexagonal manganites
• Spin-dependent polaron formation dynamics in Eu${}_{0.75}$Y${}_{0.25}$MnO${}_3$ probed by femtosecond pump-probe spectroscopy

Cited by in corpus (8)

• How to manipulate magnetic states of antiferromagnets
• Coherent phonons in a $B{i}_{2}S{e}_3$ film generated by an intense single-cycle THz pulse
• Lattice-Mediated Magnetic Order Melting in TbMnO3
• 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${}_3$
• Directly probing spin dynamics in insulating antiferromagnets using ultrashort terahertz pulses
• The role of the rare earth in the lattice and magnetic coupling in multiferroic h-HoMnO3
• Ultrafast signatures of spin and orbital order in antiferromagnetic $\alpha$-Sr${}_2$CrO${}_4$