TY  - JOUR
A1  - Enquist, Henrik
A1  - Navirian, Hengameh
A1  - Nueske, Ralf
A1  - von Korff Schmising, Clemens
A1  - Jurgilaitis, Andrius
A1  - Herzog, Marc
A1  - Bargheer, Matias
A1  - Sondhauss, Peter
A1  - Larsson, Joergen
T1  - Subpicosecond hard x-ray streak camera using single-photon counting
N2  - We have developed and characterized a hard x-ray accumulating streak camera that achieves subpicosecond time resolution by using single-photon counting. A high repetition rate of 2 kHz was achieved by use of a readout camera with built-in image processing capabilities. The effects of sweep jitter were removed by using a UV timing reference. The use of single-photon counting allows the camera to reach a high quantum efficiency by not limiting the divergence of the photoelectrons.
Y1  - 2010
UR  - http://www.opticsinfobase.org/
U6  - https://doi.org/10.1364/OL.35.003219
SN  - 0146-9592
ER  - 
TY  - JOUR
A1  - Shayduk, Roman
A1  - Navirian, Hengameh
A1  - Leitenberger, Wolfram
A1  - Goldshteyn, Jevgenij
A1  - Vrejoiu, Ionela
A1  - Weinelt, Martin
A1  - Gaal, Peter
A1  - Herzog, Marc
A1  - von Korff Schmising, Clemens
A1  - Bargheer, Matias
T1  - Nanoscale heat transport studied by high-resolution time-resolved x-ray diffraction
JF  - New journal of physics : the open-access journal for physics
N2  - We report on synchrotron-based high-repetition rate ultrafast x-ray diffraction (UXRD) experiments monitoring the transport of heat from an epitaxial La(0.7)Sr(0.3)MnO(3)/SrTiO(3) superlattice (SL) into the substrate on timescales from 100 ps to 4 mu s. Transient thermal lattice expansion was determined with an accuracy of 10(-7), corresponding to a sensitivity to temperature changes down to 0.01 K. We follow the heat flow within the SL and into the substrate after the impulsive laser heating leads to a small temperature rise of Delta T = 6 K. The transient lattice temperature can be simulated very well using the bulk heat conductivities. This contradicts the interpretation of previous UXRD measurements, which predicted a long-lasting expansion of SrRuO(3) for more than 200 ps. The disagreement could be resolved by assuming that the heat conductivity changes in the first hundred picoseconds.
Y1  - 2011
U6  - https://doi.org/10.1088/1367-2630/13/9/093032
SN  - 1367-2630
VL  - 13
IS  - 11
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Shayduk, Roman
A1  - Herzog, Marc
A1  - Bojahr, Andre
A1  - Schick, Daniel
A1  - Gaal, Peter
A1  - Leitenberger, Wolfram
A1  - Navirian, Hengameh
A1  - Sander, Mathias
A1  - Goldshteyn, Jevgenij
A1  - Vrejoiu, Ionela
A1  - Bargheer, Matias
T1  - Direct time-domain sampling of subterahertz coherent acoustic phonon spectra in SrTiO3 using ultrafast x-ray diffraction
JF  - Physical review : B, Condensed matter and materials physics
N2  - We synthesize sub-THz longitudinal quasimonochromatic acoustic phonons in a SrTiO3 single crystal using a SrRuO3/SrTiO3 superlattice as an optical-acoustic transducer. The generated acoustic phonon spectrum is determined using ultrafast x-ray diffraction. The analysis of the generated phonon spectrum in the time domain reveals a k-vector dependent phonon lifetime. It is observed that even at sub-THz frequencies the phonon lifetime agrees with the 1/omega(2) power law known from Akhiezer's model for hyper sound attenuation. The observed shift of the synthesized spectrum to the higher q is discussed in the framework of nonlinear effects appearing due to the high amplitude of the synthesized phonons.
Y1  - 2013
U6  - https://doi.org/10.1103/PhysRevB.87.184301
SN  - 1098-0121
VL  - 87
IS  - 18
PB  - American Physical Society
CY  - College Park
ER  -