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arXiv · 1411.5135

Anharmonic Decay of Coherent Optical Phonons in Antimony

Muneaki Hase·Kiminori Ushida·Masahiro Kitajima
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Abstract

Anharmonic decay of coherent optical phonons in semimetal Sb has been investigated by using a femtosecond pump-probe technique. The coherent $A_{1g}$ mode is observed in time domain in a wide temperature range of 7 - 290 K. The decay rate (the inverse of the dephasing time) systematically increases as the lattice temperature increases, which is well explained by anharmonic phonon-phonon coupling, causing decay of the optical phonon into two acoustic phonon modes. The frequency of the $A_{1g}$ mode decreases with the temperature, which is interpreted to the results of both thermal expansion and anharmonic phonon-phonon coupling. The temperature dependence of the amplitude of the coherent $A_{1g}$ mode exhibits a decrease with the lattice temperature, which is well reproduced by considering the peaked intensity of spontaneous Raman scattering assuming a Lorentzian line shape with the linewidth controlled by the anharmonic decay, and this model can be applicable to other metallic system, like Zn.

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Muneaki Hase, Kiminori Ushida, Masahiro Kitajima. 2014-11-19. Anharmonic Decay of Coherent Optical Phonons in Antimony. https://doi.org/10.7566/jpsj.84.024708

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