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.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.