TY  - JOUR
A1  - Herzog, Marc
A1  - Bojahr, Andre
A1  - Goldshteyn, J.
A1  - Leitenberger, Wolfram
A1  - Vrejoiu, I.
A1  - Khakhulin, D.
A1  - Wulff, M.
A1  - Shayduk, Roman
A1  - Gaal, P.
A1  - Bargheer, Matias
T1  - Detecting optically synthesized quasi-monochromatic sub-terahertz phonon wavepackets by ultrafast x-ray diffraction
JF  - Applied physics letters
N2  - We excite an epitaxial SrRuO3 thin film transducer by a pulse train of ultrashort laser pulses, launching coherent sound waves into the underlying SrTiO3 substrate. Synchrotron-based x-ray diffraction (XRD) data exhibiting separated sidebands to the substrate peak evidence the excitation of a quasi-monochromatic phonon wavepacket with sub-THz central frequency. The frequency and bandwidth of this sound pulse can be controlled by the optical pulse train. We compare the experimental data to combined lattice dynamics and dynamical XRD simulations to verify the coherent phonon dynamics. In addition, we observe a lifetime of 130 ps of such sub-THz phonons in accordance with the theory.
KW  - acoustic waves
KW  - epitaxial layers
KW  - phonon dispersion relations
KW  - terahertz waves
KW  - thin film devices
KW  - X-ray diffraction
Y1  - 2012
U6  - https://doi.org/10.1063/1.3688492
SN  - 0003-6951
VL  - 100
IS  - 9
PB  - American Institute of Physics
CY  - Melville
ER  - 
TY  - JOUR
A1  - Schick, Daniel
A1  - Bojahr, Andre
A1  - Herzog, Marc
A1  - Gaal, P.
A1  - Vrejoiu, I.
A1  - Bargheer, Matias
T1  - Following Strain-Induced Mosaicity Changes of Ferroelectric Thin Films by Ultrafast Reciprocal Space Mapping
JF  - Physical review letters
N2  - We investigate coherent phonon propagation in a thin film of ferroelectric PbZr0.2Ti0.8O3 (PZT) by ultrafast x-ray diffraction experiments, which are analyzed as time-resolved reciprocal space mapping in order to observe the in-and out-of-plane structural dynamics, simultaneously. The mosaic structure of the PZT leads to a coupling of the excited out-of-plane expansion to in-plane lattice dynamics on a picosecond time scale, which is not observed for out-of-plane compression.
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevLett.110.095502
SN  - 0031-9007
SN  - 1079-7114
VL  - 110
IS  - 9
PB  - American Physical Society
CY  - College Park
ER  -