Direct time-domain sampling of subterahertz coherent acoustic phonon spectra in SrTiO3 using ultrafast x-ray diffraction

Article

关键词: GENERATION;    EXCITATION;    SUPERLATTICES;    SCATTERING;    BRILLOUIN;    CRYSTALS;    PULSES;    WAVES;   

DOI  :  10.1103/PhysRevB.87.184301

来源: SCIE

【 摘 要 】

We synthesize sub-THz longitudinal quasimonochromatic acoustic phonons in a SrTiO3 single crystal using a SrRuO3/SrTiO3 superlattice as an optical-acoustic transducer. The generated acoustic phonon spectrum is determined using ultrafast x-ray diffraction. The analysis of the generated phonon spectrum in the time domain reveals a k-vector dependent phonon lifetime. It is observed that even at sub-THz frequencies the phonon lifetime agrees with the 1/omega(2) power law known from Akhiezer's model for hyper sound attenuation. The observed shift of the synthesized spectrum to the higher q is discussed in the framework of nonlinear effects appearing due to the high amplitude of the synthesized phonons.

【 授权许可】

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