TY  - JOUR
AU  - Linker, Thomas M.
AU  - Halavanau, Aliaksei
AU  - Kroll, Thomas
AU  - Benediktovitch, Andrei
AU  - Zhang, Yu
AU  - Michine, Yurina
AU  - Chuchurka, Stasis
AU  - Abhari, Zain
AU  - Ronchetti, Daniele
AU  - Fransson, Thomas
AU  - Weninger, Clemens
AU  - Fuller, Franklin D.
AU  - Aquila, Andy
AU  - Alonso-Mori, Roberto
AU  - Boutet, Sebastien
AU  - Guetg, Marc W.
AU  - Marinelli, Agostino
AU  - Lutman, Alberto A.
AU  - Yabashi, Makina
AU  - Inoue, Ichiro
AU  - Osaka, Taito
AU  - Yamada, Jumpei
AU  - Inubushi, Yuichi
AU  - Yamaguchi, Gota
AU  - Hara, Toru
AU  - Babu, Ganguli
AU  - Salpekar, Devashish
AU  - Sayed, Farheen N.
AU  - Ajayan, Pulickel M.
AU  - Kern, Jan
AU  - Yano, Junko
AU  - Yachandra, Vittal K.
AU  - Kling, Matthias F.
AU  - Pellegrini, Claudio
AU  - Yoneda, Hitoki
AU  - Rohringer, Nina
AU  - Bergmann, Uwe
TI  - Attosecond Inner-Shell Lasing at Angstrom Wavelengths
JO  - Nature
VL  - 642
IS  - arXiv:2409.06914
SN  - 0028-0836
CY  - London [u.a.]
PB  - Nature Publ. Group
M1  - PUBDB-2025-01093
M1  - arXiv:2409.06914
SP  - 934 – 940
PY  - 2025
AB  - Since the invention of the laser nonlinear effects such as filamentation, Rabi-cycling and collective emission have been explored in the optical regime leading to a wide range of scientific and industrial applications. X-ray free electron lasers (XFELs) have led to the extension of many optical techniques to X-rays for their advantages of angstrom scale spatial resolution and elemental specificity. One such example is XFEL driven population inversion of 1s core hole states resulting in inner-shell Kα (2p to 1s) X-ray lasing in elements ranging from neon to copper, which has been utilized for nonlinear spectroscopy and development of next generation X-ray laser sources. Here we show that strong lasing effects, similar to those observed in the optical regime, can occur at 1.5 to 2.1 angstrom wavelengths during high intensity (> 10<sup>19</sup> W/cm<sup>2</sup>) XFEL driven inner-shell lasing and superfluorescence of copper and manganese. Depending on the temporal substructure of the XFEL pump pulses(containing  10<sup>6</sup> - 10<sup>8</sup> photons) i, the resulting inner-shell X-ray laser pulses can exhibit strong spatial inhomogeneities as well as spectral splitting, inhomogeneities and broadening. Through 3D Maxwell Bloch theory we show that the observed spatial inhomogeneities result from X-ray filamentation, and that the spectral splitting and broadening is driven by Rabi cycling with sub-femtosecond periods. Our simulations indicate that these X-ray pulses can have pulse lengths of less than 100 attoseconds and coherence properties that open the door for quantum X-ray optics applications.
KW  - Optics (physics.optics) (Other)
KW  - Atomic Physics (physics.atom-ph) (Other)
KW  - FOS: Physical sciences (Other)
LB  - PUB:(DE-HGF)16
C6  - pmid:40500439
DO  - DOI:10.1038/s41586-025-09105-9
UR  - https://bib-pubdb1.desy.de/record/625317
ER  -