Complementary detection of confined acoustic phonons in quantum dots by coherent phonon measurement and Raman scattering - art. no. 201315

Coherent acoustic phonon oscillation is observed in PbSe quantum dots embed ded in phosphate glass by femtosecond pump-and-probe. The size dependence o f the oscillation is investigated. Distinct low-frequency peaks are observe d in Raman spectrum for the same samples. The size-dependence of the freque ncies is well explained by elastic sphere model, but the observed modes are different to each other for coherent phonon and Raman scattering. Coherent phonon measurement and Raman scattering are found to give complementary in formation on confined acoustic phonons in this system.