@article{SokolowskiTintenBlomeBlumsetal., author = {Sokolowski-Tinten, Klaus and Blome, Christian and Blums, Juris and Dietrich, Clemens and Tarsevitch, Alexander and Horn-von Hoegen, Michael and von der Linde, Dietrich and Cavalleri, Andrea and Kammler, Martin and Uschmann, Ingo and Foerster, Eckhart}, title = {Femtosecond X-ray Diffraction Study of Large Amplitude Coherent Optical Phonons in Laser-Excited Bismuth}, series = {Conference on Lasers and Electro-Optics, 1-6 June 2003, Baltimore, Maryland}, journal = {Conference on Lasers and Electro-Optics, 1-6 June 2003, Baltimore, Maryland}, publisher = {Optical Society of America}, abstract = {Femtosecond time-resolved X-ray diffraction was used to directly study optical phonons in laser-excited Bismuth. A periodic modulation of the diffraction efficiency reveals initially coherent lattice distortions with atomic displacements of nearly 10\% of the nearest- neighbor-distance.}, language = {en} } @inproceedings{SidersCavalleriTothetal., author = {Siders, C. W. and Cavalleri, Andrea and T{\´o}th, Csaba and Wilson, K. R. and Squier, Jeff A. and Barty, C. P. J. and Kammler, Martin and Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D.}, title = {Femtosecond X-ray diffraction of short-pulse irradiated semiconductors}, series = {Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges, 24-24 May 2002, Long Beach, CA, USA}, booktitle = {Summaries of Papers Presented at the Lasers and Electro-Optics. CLEO '02. Technical Diges, 24-24 May 2002, Long Beach, CA, USA}, publisher = {IEEE}, doi = {10.1109/CLEO.2002.1033997}, pages = {297 -- 298}, abstract = {Summary form only given, as follow. Ultrafast optical-pump, X-ray diffraction probe experiments are providing new ways to study transient processes including the direct observation of the atomic motion by which many solid-state processes and chemical and biochemical reactions take place. Current table-top-terawatt femtosecond laser systems provide an attractive source of few-hundred femtosecond duration bursts of angstrom-scale X-ray radiation with fluxes comparable to standard rotating anode sources. Their compact size enables time resolved structural dynamics to be studied in the small laboratory with temporal resolution better than typical molecular vibrational periods. Ultrafast structural dynamics in crystalline samples are readily studied with such systems and experiments to be discussed in this talk include ultrafast non-thermal solid-to-liquid transition in thin single-crystal Ge-111 films grown on Si-111 substrates; ultrafast non-thermal solid-to-solid transitions in bulk vanadium dioxide from a low temperature insulating phase to a high temperature metallic phase; and harmonic and anharmonic coherent acoustic dynamics in layered Ge-111/Si-111 and bulk GaAs-111 samples. Future improvements in high-average power short-pulse lasers will enable the study of a wider class of materials such as amorphous solids or liquid-phase dynamics of simple molecules, while proposed 4th generation light sources based upon single-pass X-ray free-electron lasers will permit singleshot structural determination of complex biomolecules.}, language = {en} } @article{SokolowskiTintenBlomeBlumsetal., author = {Sokolowski-Tinten, Klaus and Blome, Christian and Blums, Juris and Cavalleri, Andrea and Dietrich, Clemens and Tarasevitch, Alexander and Uschmann, Ingo and F{\"o}rster, Eckhard and Kammler, Martin and Horn-von Hoegen, Michael and von der Linde, Dietrich}, title = {Femtosecond X-ray measurement of coherent lattice vibrations near the Lindemann stability limit}, series = {Nature}, volume = {422}, journal = {Nature}, number = {6929}, publisher = {Springer}, doi = {10.1038/nature01490}, pages = {287 -- 289}, abstract = {The study of phase-transition dynamics in solids beyond a time-averaged kinetic description requires direct measurement of the changes in the atomic configuration along the physical pathways leading to the new phase. The timescale of interest is in the range 10(-14) to 10(-12) s. Until recently, only optical techniques were capable of providing adequate time resolution, albeit with indirect sensitivity to structural arrangement. Ultrafast laser-induced changes of long-range order have recently been directly established for some materials using time-resolved X-ray diffraction. However, the measurement of the atomic displacements within the unit cell, as well as their relationship with the stability limit of a structural phase, has to date remained obscure. Here we report time-resolved X-ray diffraction measurements of the coherent atomic displacement of the lattice atoms in photoexcited bismuth close to a phase transition. Excitation of large-amplitude coherent optical phonons gives rise to a periodic modulation of the X-ray diffraction efficiency. Stronger excitation corresponding to atomic displacements exceeding 10 per cent of the nearest-neighbour distance-near the Lindemann limit-leads to a subsequent loss of long-range order, which is most probably due to melting of the material.}, language = {en} } @article{SokolowskiTintenHornvonHoegenvonderLindeetal., author = {Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and Leitner, D. M. and T{\´o}th, Csaba and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R. and Kammler, Martin}, title = {Transient lattice dynamics in fs-laser-excited semiconductors probed by ultrafast X-ray diffraction}, series = {Journal de Physique IV}, volume = {11}, journal = {Journal de Physique IV}, number = {Pr2}, publisher = {EDP}, doi = {10.1051/jp4:2001290}, pages = {473 -- 477}, abstract = {A study of lattice dynamics in fs-laser-excited crystalline bulk Ge and Ge/Si-heterostructures, using time-resolved x-ray diffraction, was presented. Fast energy transport deep into the bulk of the material, coherent acoustic phonon dynamics, lattice anharmonicity, and vibrational transport across a buried interfaces were observed. Graphs showing time-dependent shifts of the centroid of the measured rocking curves in the Ge-overlayer and in the Si-substrate for different fluences, were presented.}, language = {en} } @article{SokolowskiTintenCavalleriSidersetal., author = {Sokolowski-Tinten, Klaus and Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and Leitner, D. M. and T{\´o}th, Csaba and Kammler, Martin and Horn-von Hoegen, Michael and von der Linde, D. and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R.}, title = {Time-resolved x-ray diffraction study of ultrafast acoustic phonon dynamics in Ge/Si-heterostructures}, series = {Chemical Physics}, volume = {66}, journal = {Chemical Physics}, publisher = {Springer}, doi = {10.1007/978-3-642-56546-5_81}, pages = {281 -- 283}, abstract = {Using time-resolved x-ray diffraction the ultafast strain dynamics in fs-laserexcited Ge/Si-heterostructures has been studied. A fluence dependent, anharmonic damping of the impulsively generated acoustic phonons and vibrational transport across the buried Ge/Si-interface are observed.}, language = {en} } @inproceedings{SokolowskiTintenBlomeDietrichetal., author = {Sokolowski-Tinten, Klaus and Blome, Christian and Dietrich, Clemens and Blums, Juris and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Squier, Jeff A. and Kammler, Martin}, title = {Structural dynamics in laser-excited solids investigated with femtosecond x-ray diffraction}, series = {2002 Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference, 19-24 May 2002, Long Beach, CA, USA}, booktitle = {2002 Summaries of Papers Presented at the Quantum Electronics and Laser Science Conference, 19-24 May 2002, Long Beach, CA, USA}, publisher = {IEEE}, doi = {10.1109/QELS.2002.1031182}, pages = {115 -- 116}, abstract = {Summary form only given. Ultrashort x-ray pulses offer a unique combination of atomic-scale spatial and temporal resolution, which permits direct measurements of structural transients on an ultrafast time scale. Using time-resolved X-ray diffraction with femtosecond, multi-keV X-ray pulses we have studied transient lattice dynamics in optically excited semiconductors.}, language = {en} } @article{SokolowskiTintenBlomeDietrichetal., author = {Sokolowski-Tinten, Klaus and Blome, Christian and Dietrich, Clemens and Tarasevitch, A. and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Squier, Jeff A. and Kammler, Martin}, title = {Femtosecond x-ray measurement of ultrafast melting and large acoustic transients}, series = {Physical review letters}, volume = {87}, journal = {Physical review letters}, publisher = {APS}, doi = {10.1103/PhysRevLett.87.225701}, abstract = {Time-resolved x-ray diffraction with ultrashort ( approximately 300 fs), multi-keV x-ray pulses has been used to study the femtosecond laser-induced solid-to-liquid phase transition in a thin crystalline layer of germanium. Nonthermal melting is observed to take place within 300-500 fs. Following ultrafast melting we observe strong acoustic perturbations evolving on a picosecond time scale.}, language = {en} } @article{SokolowskiTintenBlomeDietrichetal., author = {Sokolowski-Tinten, Klaus and Blome, Christian and Dietrich, Clemens and Tarasevitch, A. and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Squier, Jeff A. and Kammler, Martin}, title = {Femtosecond time-resolved X-ray diffraction study of ultrafast structural dynamics in laser-excited solids}, series = {International Conference on Ultrafast Phenomena, 12 May 2002, Vancouver Canada}, volume = {71}, journal = {International Conference on Ultrafast Phenomena, 12 May 2002, Vancouver Canada}, publisher = {Optica Publishing Grou}, doi = {10.1007/978-3-642-59319-2_10}, pages = {36 -- 38}, abstract = {Time-resolved x-ray diffraction with sub-300 fs, multi-keV x-ray pulses was used to study ultrafast lattice dynamics in laser-irradiated germanium and bismuth. In bismuth strong excitation of optical phonons is observed prior to disordering of the material.}, language = {en} } @article{CavalleriSidersBrownetal., author = {Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and Leitner, D. M. and T{\´o}th, Csaba and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R. and Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D. and Kammler, Martin}, title = {Anharmonic lattice dynamics in germanium measured with ultrafast x-ray diffraction}, series = {Physical review letters}, volume = {85}, journal = {Physical review letters}, number = {3}, publisher = {APS}, doi = {10.1103/PhysRevLett.85.586}, pages = {586 -- 589}, abstract = {Damping of impulsively generated coherent acoustic oscillations in a femtosecond laser-heated thin germanium film is measured as a function of fluence by means of ultrafast x-ray diffraction. By simultaneously measuring picosecond strain dynamics in the film and in the unexcited silicon substrate, we separate anharmonic damping from acoustic transmission through the buried interface. The measured damping rate and its dependence on the calculated temperature of the thermal bath is consistent with estimated four-body, elastic dephasing times (T2) for 7-GHz longitudinal acoustic phonons in germanium.}, language = {en} } @article{SokolowskiTintenHornvonHoegenvonderLindeetal., author = {Sokolowski-Tinten, Klaus and Horn-von Hoegen, Michael and von der Linde, D. and Cavalleri, Andrea and Siders, C. W. and Brown, F. L. H. and T{\´o}th, Csaba and Squier, Jeff A. and Barty, C. P. J. and Wilson, K. R. and Kammler, Martin}, title = {Time-resolved x-ray diffraction study of ultrafast acoustic phonon dynamics in Ge/Si-heterostructures}, series = {International Conference on Ultrafast Phenomena , 9 July 2000, Charleston}, journal = {International Conference on Ultrafast Phenomena , 9 July 2000, Charleston}, publisher = {Optica}, abstract = {Using time-resolved x-ray diffraction the ultafast strain dynamics in fs-laserexcited Ge/Si-heterostructures has been studied. A fluence dependent, anharmonic damping of the impulsively generated acoustic phonons and vibrational transport across the buried Ge/Si-interface are observed.}, language = {en} } @article{SidersCavalleriSokolowskiTintenetal., author = {Siders, C. W. and Cavalleri, Andrea and Sokolowski-Tinten, Klaus and T{\´o}th, Csaba and Guo, T. and Kammler, Martin and Horn-von Hoegen, Michael and Wilson, K. R. and von der Linde, D. and Barty, C. P. J.}, title = {Detection of nonthermal melting by ultrafast X-ray diffraction}, series = {Science}, volume = {286}, journal = {Science}, number = {5443}, doi = {10.1126/science.286.5443.1340}, pages = {1340 -- 1342}, abstract = {Using ultrafast, time-resolved, 1.54 angstrom x-ray diffraction, thermal and ultrafast nonthermal melting of germanium, involving passage through nonequilibrium extreme states of matter, was observed. Such ultrafast, optical-pump, x-ray diffraction probe measurements provide a way to study many other transient processes in physics, chemistry, and biology, including direct observation of the atomic motion by which many solid-state processes and chemical and biochemical reactions take place.}, language = {en} } @article{SidersCavalleriSokolowskiTintenetal., author = {Siders, C. W. and Cavalleri, Andrea and Sokolowski-Tinten, Klaus and T{\´o}th, Csaba and Guo, T. and Kammler, Martin and Horn-von Hoegen, Michael and Wilson, K. R. and von der Linde, D. and Barty, C. P. J.}, title = {Direct Observation of Ultrafast Non-thermal Melting by Ultrafast X-ray Diffraction}, series = {Ultrafast Phenomena XII}, volume = {66}, journal = {Ultrafast Phenomena XII}, publisher = {Springer}, doi = {10.1007/978-3-642-56546-5_80}, pages = {276 -- 280}, abstract = {Ultrafast nonthermal melting of femtosecond laser-irradiated germanium was observed directly for the first time using sub-picosecond, 1.54-angstrom x-ray diffraction. Such measurements allow the study of transient atomic motion fundamental to many processes in physics, chemistry, and biology.}, language = {en} } @incollection{SokolowskiTintenvonderLindeSidersetal., author = {Sokolowski-Tinten, Klaus and von der Linde, D. and Siders, C. W. and Cavalleri, Andrea and T{\´o}th, Csaba and Guo, T. and Wilson, K. R. and Barty, C. P. J. and Kammler, Martin and Horn-von Hoegen, Michael}, title = {Lattice dynamics of femtosecond laser-excited semiconductors probed by ultrafast x-ray diffraction}, series = {Applications of High Field and Short Wavelength Sources VIII}, booktitle = {Applications of High Field and Short Wavelength Sources VIII}, publisher = {Optica}, doi = {10.1364/HFSW.1999.PD3}, abstract = {The present knowledge of the atomic structure of matter is to a large extent due to x-ray spectroscopies.}, language = {en} } @article{SokolowskiTintenBlomeBlumsetal., author = {Sokolowski-Tinten, Klaus and Blome, Christian and Blums, Juris and Shymanovich, Uladzimir and Nicoul, Matthieu and Cavalleri, Andrea and Tarasevitch, A. and Horn-von Hoegen, Michael and Kammler, Martin and von der Linde, D.}, title = {Ultrafast X-ray diffraction}, series = {Ultrafast Phenomena XIV}, volume = {79}, journal = {Ultrafast Phenomena XIV}, publisher = {Springer}, doi = {10.1007/3-540-27213-5_53}, pages = {170 -- 174}, abstract = {In the last few years the generation of femtosecond pulses in the X-ray regime has become possible. These ultrashort X-ray pulses have enabled femtosecond time- resolution to be extended to X-rays.}, language = {en} } @inproceedings{SokolowskiTintenBlomeBlumsetal., author = {Sokolowski-Tinten, Klaus and Blome, Christian and Blums, Juris and Shymanovich, Uladzimir and Nicoul, Matthieu and Cavalleri, Andrea and Tarasevitch, A. and Horn-von Hoegen, Michael and Kammler, Martin and von der Linde, Dietrich}, title = {Ultrafast X-ray diffraction}, series = {Ultrafast Phenomena XIV}, volume = {79}, booktitle = {Ultrafast Phenomena XIV}, editor = {Kobayashi, Tetsuro}, publisher = {Springer}, address = {Berlin, Heidelberg}, isbn = {978-3-540-27213-7}, doi = {10.1007/3-540-27213-5_53}, pages = {170 -- 174}, abstract = {In the last few years the generation of femtosecond pulses in the X-ray regime has become possible. These ultrashort X-ray pulses have enabled femtosecond time- resolution to be extended to X-rays.}, language = {en} }