Presentation Information
[10a-PB2-2]Excitation of Rotational Phonons in BiFeO3 by Phase-Controlled ISRS
〇(M1)Keitatsu Yamamoto1, Gakuto Kusuno1, Toshimitsu Ito2, Takuya Satoh1 (1.Science Tokyo., 2.AIST.)
Keywords:
Rotational phonon,ISRS,Multiferroic BiFeO3
Multiferroic BiFeO3 (BFO) is attractive for spintronic applications because it exhibits ferroelectricity and antiferromagnetism at room temperature. BFO has degenerate E-mode phonons; exciting two orthogonal components with a relative phase of π/2 can generate rotational phonons, in which atomic displacements rotate in the plane and carry angular momentum.We generated rotational phonons in a BFO single crystal using phase-controlled impulsive stimulated Raman scattering (ISRS). Femtosecond pump pulses at 1300 nm were split into two beams with orthogonal polarizations and a pump–pump delay corresponding to a π/2 phase difference. Coherent phonon responses were measured by transmission pump–probe spectroscopy using 800 nm probe pulses.By tuning the pump–pump delay, we controlled the amplitude and phase of the two E-mode components. The reconstructed trajectory showed in-plane circular motion, and Fourier analysis revealed a peak around 2.3 THz, corresponding to the BFO E-mode phonon.