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## Time-Resolved Autoionization using Attosecond Pulses

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**Marlene Wickenhauser and Joachim Burgdörfer**Inst. for Theoretical Physics, Vienna University of Technology, AUSTRIA Ferenc Krausz Max-Planck-Inst. for Quantum Optics, Garching, Germany Markus Drescher Faculty of Physics University of Bielefeld, GERMANY Time-Resolved Autoionization using Attosecond Pulses**Time resolved atomic dynamics**Goal: Time resolved electron wave packet Time scale of electronic motion: ~100 as**Pump probe experiment**momentum shift: = delay time energy probe pulse t 2.5 fs energy gas atom pump pulse 500 as**energy**Motiation: Auger decay M. Drescher F. Krausz (2002) Auger line 40 eV Spectra for different delay times extract lifetime of Auger decay**Autoionization: Coherent excitation**super Coster Kronig Cr:tr = 800 as schematic: Goal: Time resolved evolution of coherent superposition**Fano line shape in emission spectrum**intensity window resonance G energy**Spectrum: Fano profile**excitation amplitude to resonant state q ~ excitation amplitude to continuum q = 2 q = 1 q = 0 energy**Approximations:**Model Hamiltonian: Laser bound-continuum coupling • XUV-pump pulse: • First order perturbation theory • Probe pulse: • Strong field approximation**Time dependent ionization probability**for window resonance (q = 0) intensity XUV-pump pulse time energy**Simulated Pump Probe Spectra**direct ionization without resonance Auger decay Fano resonance (q = 0.5) tr = 500 as tr = 500 as 30 40 50 Energy (eV) energy 0 1 2 3 4 5 time delay time delay time delay (fs) tr = 2.5 fs tr = 2.5 fs energy time delay time delay**q = 0: window resonance**30 40 50 energy 0 1 2 delay time (fs) envelope of time differential ionization probability: A B A “A+B” B t energy**Complex q ?**• Resonances in magnetic field • Decoherence in open quantum systems System with broken time reversal symmetry**Time-integral spectrum**probability**B = 0.9160**B = 0.9151 B = 0.9142 Example: quantum dot K. Kobayashi, H. Aikawa, S. Katsumoto and Y. Iye Phys. Rev. B 68, 235304 (2003) Fano resonance in presence of magnetic field:**Can time resolved spectroscopy distinguish q=+/- i ?**energy energy delay time delay time intensity intensity time time energy energy q = - i q = i**A(E) = Aresonant + Adirect + Acorrection**q = i q = - i constructive interference destructive interference**Summary**• Time evolution of an autoionizing resonance • Simulate pump probe experiment • Analyze case of complex Fano parameter