Observation of photo-induced plasmon-phonon coupling in PbTe via ultrafast x-ray scattering.
Struct Dyn
; 9(2): 024301, 2022 Mar.
Article
in En
| MEDLINE
| ID: mdl-35311000
ABSTRACT
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.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Struct Dyn
Year:
2022
Document type:
Article