Details

Autor(en) / Beteiligte

• Ott, Christian
• Kaldun, Andreas
• Raith, Philipp
• Meyer, Kristina
• Laux, Martin
• Evers, Jörg
• Keitel, Christoph H.
• Greene, Chris H.
• Pfeifer, Thomas

Titel

Lorentz Meets Fano in Spectral Line Shapes: A Universal Phase and Its Laser Control

Ist Teil von

• Science (American Association for the Advancement of Science), 2013-05, Vol.340 (6133), p.716-720

Ort / Verlag

Washington, DC: American Association for the Advancement of Science

Erscheinungsjahr

2013

Quelle

American Association for the Advancement of Science

Beschreibungen/Notizen

• Symmetric Lorentzian and asymmetric Fano line shapes are fundamental spectroscopic signatures that quantify the structural and dynamical properties of nuclei, atoms, molecules, and solids. This study introduces a universal temporal-phase formalism, mapping the Fano asymmetry parameter q to a phase φ of the time-dependent dipole response function. The formalism is confirmed experimentally by laser-transforming Fano absorption lines of autoionizing helium into Lorentzian lines after attosecond-pulsed excitation. We also demonstrate the inverse, the transformation of a naturally Lorentzian line into a Fano profile. A further application of this formalism uses quantum-phase control to amplify extreme-ultraviolet light resonantly interacting with He atoms. The quantum phase of excited states and its response to interactions can thus be extracted from line-shape analysis, with applications in many branches of spectroscopy.