2014/09/24 by Paul Fons, Peter Rodenbach, Kirill V. Mitrofanov +10 · 25 citations
Chemistry · Engineering · Materials Science · Physics and Astronomy · #Analytical Chemistry (journal) #Atomic physics #Chalcogenide Semiconductor Thin Films #Chemistry #Condensed matter physics #Diffraction #Excitation #Femtosecond #Laser #Materials science #Molecular physics #Nonlinear Optical Materials Studies #Optics #Phase-change materials and chalcogenides #Phonon #Physics #Picosecond #Thermal #Thermodynamics #Ultrashort pulse #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.90.094305
published in Physical Review B 90(9) (American Physical Society) · 7 pages, 4 figures, Phys. Rev. B, in press
arxiv created 2014/09/24 · openalex publication_date 2014/09/25 · arxiv updated 2014/09/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Coherent phonons (CPs) generated by laser pulses on the femtosecond scale have been proposed as a means to achieve ultrafast, nonthermal switching in phase-change materials such as Ge2Sb2Te5 (GST). Here we use ultrafast optical pump pulses to induce coherent acoustic phonons and stroboscopically measure the corresponding lattice distortions in GST using 100-ps x-ray pulses from the European Synchrotron Radiation Facility (ESRF) storage ring. A linear-chain model provides a good description of the observed changes in the diffraction signal; however, the magnitudes of the measured shifts are too large to be explained by thermal effects alone, implying the presence of excited-state effects in addition to temperature-driven expansion. The information on the movement of atoms during the excitation process can lead to greater insight into the possibilities of using CP-induced phase transitions in GST.