Observation of terahertz magnon of Kaplan-Kittel exchange resonance in yttrium-iron garnet by Raman spectroscopy

Abstract

Backscattering Raman spectroscopic investigations were performed on an yttrium-iron garnet single crystal using linearly and circularly polarized light. A terahertz (THz) magnon of the Kaplan-Kittel (KK) exchange resonance was discovered, which had been regarded as unobservable via optical methods. The KK exchange resonance had a 7.8-THz frequency at 80 K, and the polarization selection rule led to an antisymmetric Raman tensor of the $A_2$ mode. Moreover, the assignment of all the Raman-active phonon modes, $3A_{1g}$, $8E_g$, and $14T_{2g}$, was proposed. This study will stimulate further investigation of the coupling of THz magnons and phonons and pave the way toward THz optomagnonics.

References in corpus (5)

• Hybridizing ferromagnetic magnons and microwave photons in the quantum limit
• Spin Oscillations in Antiferromagnetic NiO Triggered by Circularly Polarized Light
• Thermal spin dynamics of yttrium iron garnet
• First-Principles Study of Exchange Interactions of Yttrium Iron Garnet
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Cited by in corpus (6)

• Truly chiral phonons in α-HgS
• A review of modelling in ferrimagnetic spintronics
• Spin-Phonon Interaction in Yttrium Iron Garnet
• Ultrafast Optomagnonics in Ferrimagnetic Multi-Sublattice Garnets
• Exploring terahertz-scale exchange resonances in synthetic ferrimagnets with ultrashort optically induced spin currents
• Enhancement of thermal spin pumping by orbital angular momentum of rare earth iron garnet