Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Stimulated X-ray emission for materials science


Resonant inelastic X-ray scattering and X-ray emission spectroscopy can be used to probe the energy and dispersion of the elementary low-energy excitations that govern functionality in matter: vibronic, charge, spin and orbital excitations1,2,3,4,5,6,7. A key drawback of resonant inelastic X-ray scattering has been the need for high photon densities to compensate for fluorescence yields of less than a per cent for soft X-rays8. Sample damage from the dominant non-radiative decays thus limits the materials to which such techniques can be applied and the spectral resolution that can be obtained. A means of improving the yield is therefore highly desirable. Here we demonstrate stimulated X-ray emission for crystalline silicon at photon densities that are easily achievable with free-electron lasers9. The stimulated radiative decay of core excited species at the expense of non-radiative processes reduces sample damage and permits narrow-bandwidth detection in the directed beam of stimulated radiation. We deduce how stimulated X-ray emission can be enhanced by several orders of magnitude to provide, with high yield and reduced sample damage, a superior probe for low-energy excitations and their dispersion in matter. This is the first step to bringing nonlinear X-ray physics in the condensed phase from theory10,11,12,13,14,15,16 to application.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Geometry to observe spontaneously stimulated X-ray emission from solids.
Figure 2: Observing stimulated emission from a solid.
Figure 3: Spectrally resolved stimulated emission.

Similar content being viewed by others


  1. Kotani, A. & Shin, S. Resonant inelastic x-ray scattering spectra for electrons in solids. Rev. Mod. Phys. 73, 203–246 (2001)

    Article  CAS  ADS  Google Scholar 

  2. Schlappa, J. et al. Collective magnetic excitations in the spin ladder Sr14Cu24O41 measured using high-resolution resonant inelastic x-ray scattering. Phys. Rev. Lett. 103, 047401 (2009)

    Article  CAS  ADS  Google Scholar 

  3. Hennies, F. et al. Resonant inelastic scattering spectra of free molecules with vibrational resolution. Phys. Rev. Lett. 104, 193002 (2010)

    Article  ADS  Google Scholar 

  4. Ament, L. J. P., van Veenendaal, M., Devereaux, T., Hill, J. P. & van den Brink, J. Resonant inelastic x-ray scattering studies of elementary excitations. Rev. Mod. Phys. 83, 705–767 (2011)

    Article  CAS  ADS  Google Scholar 

  5. Le Tacon, M. et al. Intense paramagnon excitations in a large family of high-temperature superconductors. Nature Phys. 7, 725–730 (2011)

    Article  CAS  ADS  Google Scholar 

  6. Pietzsch, A. et al. Spatial quantum beats in vibrational resonant inelastic soft x-ray scattering at dissociating states in oxygen. Phys. Rev. Lett. 106, 153004 (2011)

    Article  CAS  ADS  Google Scholar 

  7. Schlappa, J. et al. Spin-orbital separation in the quasi-one-dimensional mott insulator Sr2CuO3 . Nature 485, 82–85 (2012)

    Article  CAS  ADS  Google Scholar 

  8. Krause, M. O. Atomic radiative and radiationless yields for K and L shells. J. Phys. Chem. Ref. Data 8, 307 (1979)

    Article  CAS  ADS  Google Scholar 

  9. McNeil, B. W. J. & Thompson, N. R. X-ray free-electron lasers. Nature Photon. 4, 814–821 (2010)

    Article  CAS  ADS  Google Scholar 

  10. Tanaka, S. & Mukamel, S. Coherent x-ray Raman spectroscopy: a nonlinear local probe for electronic excitations. Phys. Rev. Lett. 89, 043001 (2002)

    Article  ADS  Google Scholar 

  11. Mukamel, S. Multiple core-hole coherence in x-ray four-wave-mixing spectroscopies. Phys. Rev. B 72, 235110 (2005)

    Article  ADS  MathSciNet  Google Scholar 

  12. Schweigert, I. & Mukamel, S. Probing valence electronic wave-packet dynamics by all x-ray stimulated Raman spectroscopy: a simulation study. Phys. Rev. A 76, 012504 (2007)

    Article  ADS  Google Scholar 

  13. Harbola, U. & Mukamel, S. Coherent stimulated x-ray Raman spectroscopy: attosecond extension of resonant inelastic x-ray Raman scattering. Phys. Rev. B 79, 085108 (2009)

    Article  ADS  Google Scholar 

  14. Patterson, B. D. Resource letter on stimulated inelastic x-ray scattering at an XFEL. (SLAC Technical Note SLAC-TN-10-026, SLAC National Accelerator Laboratory, Menlo Park, California, 2010).

  15. Sun, Y.-P., Liu, J.-C., Wang, C.-K. & Gel'mukhanov, F. Propagation of a strong x-ray pulse: pulse compression, stimulated raman scattering, amplified spontaneous emission, lasing without inversion, and four-wave mixing. Phys. Rev. A 81, 013812 (2010)

    Article  ADS  Google Scholar 

  16. Biggs, J. D., Zhang, Y., Healion, D. & Mukamel, S. Two-dimensional stimulated resonance Raman spectroscopy of molecules with broadband x-ray pulses. J. Chem. Phys. 136, 174117 (2012)

    Article  ADS  Google Scholar 

  17. Ackermann, W. et al. Operation of a free-electron laser from the extreme ultraviolet to the water window. Nature Photon. 1, 336–342 (2007)

    Article  ADS  Google Scholar 

  18. Emma, P. et al. First lasing and operation of an angstrom-wavelength free-electron laser. Nature Photon. 4, 641–647 (2010)

    Article  CAS  ADS  Google Scholar 

  19. Di Mitri, S. et al. in Advances in X-ray Free-Electron Lasers: Radiation Schemes, X-Ray Optics, and Instrumentation (eds Tschentscher, T. & Cocco, D. ) Vol. 8078, 807802, doi:10.1117/12.886491 (Proc. SPIE, 2011)

  20. Pile, D. X-rays: first light from SACLA. Nature Photon. 5, 456–457 (2011)

    Article  CAS  ADS  Google Scholar 

  21. Rohringer, N. et al. Atomic inner-shell x-ray laser at 1.46 nanometres pumped by an x-ray free-electron laser. Nature 481, 488–491 (2012)

    Article  CAS  ADS  Google Scholar 

  22. Glover, T. E. et al. X-ray and optical wave mixing. Nature 488, 603–608 (2012)

    Article  CAS  ADS  Google Scholar 

  23. Beye, M., Sorgenfrei, F., Schlotter, W. F., Wurth, W. & Föhlisch, A. The liquid-liquid phase transition in silicon revealed by snapshots of valence electrons. Proc. Natl Acad. Sci. USA 107, 16772–16776 (2010)

    Article  CAS  ADS  Google Scholar 

  24. Wernet, P. Electronic structure in real time: mapping valence electron rearrangements during chemical reactions. Phys. Chem. Chem. Phys. 13, 16941–16954 (2011)

    Article  CAS  Google Scholar 

  25. Salén, P. et al. Experimental verification of the chemical sensitivity of two-site double core-hole states formed by an x-ray free-electron laser. Phys. Rev. Lett. 108, 153003 (2012)

    Article  ADS  Google Scholar 

  26. Yeh, J. J. & Lindau, I. Atomic subshell photoionization cross-sections and asymmetry parameters—1 ≤ z ≤ 103. Atom. Data Nucl. Data Tab. 32, 1–155 (1985)

    Article  CAS  ADS  Google Scholar 

  27. Frühling, U. et al. Single-shot terahertz-field-driven x-ray streak camera. Nature Photon. 3, 523–528 (2009)

    Article  ADS  Google Scholar 

  28. Martins, M. et al. Monochromator beamline for FLASH. Rev. Sci. Instrum. 77, 115108 (2006)

    Article  ADS  Google Scholar 

  29. Tiedtke, K. et al. The soft x-ray free-electron laser FLASH at DESY: beamlines, diagnostics and end-stations. New J. Phys. 11, 023029 (2009)

    Article  ADS  Google Scholar 

  30. Nordgren, J. Soft x-ray emission spectroscopy—preface. J. Electron Spectrosc. 110–111, ix– x (2000)

    Article  Google Scholar 

  31. Henke, B. L., Gullikson, E. M. & Davis, J. C. X-ray interactions: photoabsorption, scattering, transmission, and reflection at E = 50-30,000 eV, Z = 1-92. Atom. Data Nucl. Data Tab. 54, 181–342 (1993)

    Article  CAS  ADS  Google Scholar 

  32. Kunnus, K. et al. A setup for resonant inelastic soft x-ray scattering on liquids at free electron laser light sources. Rev. Sci. Instrum. 83, 123109 (2012)

    Article  ADS  Google Scholar 

  33. Hricovini, K. et al. Electronic structure and its dependence on local order for H/Si(111)-(1x1) surfaces. Phys. Rev. Lett. 70, 1992–1995 (1993)

    Article  CAS  ADS  Google Scholar 

Download references


We thank N. Rohringer, A. Scherz and J. Stöhr for discussions. We acknowledge support from the FLASH staff. Financial support was given to M.B. by the VolkswagenStiftung. Further support was given by the German Federal Ministry of Education and Research through the priority programme FLASH: “Matter in the light of ultrashort and extremely intense X-ray pulses” and contract number 05K10PK2, and also by the Deutsche Forschungsgemeinschaft through the graduate school: “Physics with new advanced coherent radiation sources”.

Author information

Authors and Affiliations



All authors contributed to planning parts of the experiment. Research was conducted by F.S., C.T., N.P., C.S.-L. and M.B. Data analysis and interpretation was done by M.B., S.S. and A.F. The formalism was developed and the manuscript was written by M.B. with input from all co-authors.

Corresponding author

Correspondence to M. Beye.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

PowerPoint slides

Rights and permissions

Reprints and permissions

About this article

Cite this article

Beye, M., Schreck, S., Sorgenfrei, F. et al. Stimulated X-ray emission for materials science. Nature 501, 191–194 (2013).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing