# FS-TUX

 2019-04-0216:16 [PUBDB-2019-01830] Journal Article Rohringer, N. X-ray Raman scattering: a building block for nonlinear spectroscopy Philosophical transactions of the Royal Society of London / A 377(2145), 20170471 - (2019) [10.1098/rsta.2017.0471]   Ultraintense X-ray free-electron laser pulses of attosecond duration can enable new nonlinear X-ray spectroscopic techniques to observe coherent electronic motion. The simplest nonlinear X-ray spectroscopic concept is based on stimulated electronic X-ray Raman scattering. [...] Restricted: PDF PDF (PDFA); 2019-01-3015:23 [PUBDB-2019-00875] Journal Article et al Roadmap of ultrafast x-ray atomic and molecular physics Journal of physics / B 51(3), 032003 (2018) [10.1088/1361-6455/aa9735]   X-ray free-electron lasers (XFELs) and table-top sources of x-rays based upon high harmonic generation (HHG) have revolutionized the field of ultrafast x-ray atomic and molecular physics, largely due to an explosive growth in capabilities in the past decade. XFELs now provide unprecedented intensity (1020 W cm−2) of x-rays at wavelengths down to ~1 Ångstrom, and HHG provides unprecedented time resolution (~50 attoseconds) and a correspondingly large coherent bandwidth at longer wavelengths [...] OpenAccess: PDF PDF (PDFA); 2019-01-3015:18 [PUBDB-2019-00874] Journal Article et al Stimulated X-Ray Emission Spectroscopy in Transition Metal Complexes Physical review letters 120(13), 133203 (2018) [10.1103/PhysRevLett.120.133203]   We report the observation and analysis of the gain curve of amplified $Kα$ x-ray emission from solutions of Mn(II) and Mn(VII) complexes using an x-ray free electron laser to create the $1s$ core-hole population inversion. We find spectra at amplification levels extending over 4 orders of magnitude until saturation [...] OpenAccess: PDF PDF (PDFA); 2019-01-3015:06 [PUBDB-2019-00873] Journal Article Rohringer, N. Stimulated resonant inelastic x-ray scattering with chirped, broadband pulses Physical review / A 99(1), 013425 (2019) [10.1103/PhysRevA.99.013425]   We present an approach for initiating and tracing ultrafast electron dynamics in core-excited atoms, molecules, and solids. The approach is based on stimulated resonant inelastic x-ray scattering induced by a single, chirped, broadband XUV or x-ray pulse [...] OpenAccess: PDF PDF (PDFA); 2019-01-3014:44 [PUBDB-2019-00872] Journal Article Rohringer, N. Quantum theory of superfluorescence based on two-point correlation functions Physical review / A 99(1), 013839 (2019) [10.1103/PhysRevA.99.013839]   Irradiation of a medium by short intense pulses from x-ray (XUV) free-electron lasers can result in saturated photoionization of inner electronic shells. As a result an inversion of populations between core levels appears [...] OpenAccess: PDF PDF (PDFA);