|Title||Observation of photo-induced plasmon-phonon coupling in PbTe via ultrafast x-ray scattering.|
|Publication Type||Journal Article|
|Year of Publication||2022|
|Authors||MP Jiang, S Fahy, A Hauber, ÉD Murray, I Savić, C Bray, JN Clark, T Henighan, M Kozina, AM Lindenberg, P Zalden, M Chollet, JM Glownia, MC Hoffmann, T Sato, D Zhu, O Delaire, AF May, BC Sales, R Merlin, M Trigo, and DA Reis|
|Journal||Structural Dynamics (Melville, N.Y.)|
We report the observation of photo-induced plasmon-phonon coupled modes in the group IV-VI semiconductor PbTe using ultrafast x-ray diffuse scattering at the Linac Coherent Light Source. We measure the near-zone-center excited-state dispersion of the heavily screened longitudinal optical (LO) phonon branch as extracted from differential changes in x-ray diffuse scattering intensity following above bandgap photoexcitation. We suggest that upon photoexcitation, the LO phonon-plasmon coupled (LOPC) modes themselves become coupled to longitudinal acoustic modes that drive electron band shifts via acoustic deformation potentials and possibly to low-energy single-particle excitations within the plasma and that these couplings give rise to displacement-correlations that oscillate in time with a period given effectively by the heavily screened LOPC frequency.
|Short Title||Structural Dynamics (Melville, N.Y.)|