Presentation Information

[23p-12D-5][The 55th Young Scientist Presentation Award Speech] Observation of coherent oscillation between magnons and phonons

〇Tomosato Hioki1,2, Yusuke Hashimoto2, Eiji Saitoh1,2,3,4 (1.Dept. Appl. Phys.,Univ. Tokyo, 2.AIMR Tohoku Univ., 3.Inst. AI and Beyond, Univ. Tokyo, 4.JAEA)

Keywords:

Spintronics,spin waves,Phonon

When two oscillators are coupled, once oscillation is excited on the oscillator, the amplitude is transferred to the other oscillator in time, which comes back again after the same time it took to be transferred, a phenomenon called coherent oscillation. In a magnetic material, various elementary excitations are responsible for physical properties of the material, including the excitation of lattice and magnetic order, phonons and magnons. Owing to spin-orbit and dipole-dipole interactions, phonons and magnons are coupled to each other, which could lead to the coherent oscillation between magnons and phonons if the coupling is strong enough.
In this talk, the experimental direct observation of the coherent oscillation between magnons and phonons are presented. We developed time-resolved magneto-optical imaging technique by combining conventional magneto-optical imaging and pump-and-probe spectroscopy, which enables us to obtain snapshots of spin-wave propagation dynamics in real space with a temporal resolution of sub nanoseconds. In a Bi-doped magnetic garnet, Lu2Bi1Fe3.4Ga1.6O12, we observed coherent temporal oscillation between magnons and phonons as a result of hybridization, where magnons and phonons are coherently interconverted to each other during propagation. The experimental demonstration of these dynamics of magnon-phonon hybridized waves will be presented in the talk.