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Attosecond Flashes of Light

Attosecond Flashes of Light. – Illuminating electronic quantum dynamics –. XXIII rd Heidelberg Graduate Days Lecture Series. Thomas Pfeifer InterAtto Research Group MPI – Kernphysik, Heidelberg. Contents Yesterday. Attosecond Pulses Classical and quantum mechanics of electrons.

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Attosecond Flashes of Light

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  1. Attosecond Flashes of Light – Illuminating electronic quantum dynamics – XXIIIrd Heidelberg Graduate Days Lecture Series Thomas PfeiferInterAtto Research Group MPI – Kernphysik, Heidelberg

  2. Contents Yesterday Attosecond Pulses Classical and quantum mechanics of electrons - Classical Motion of Electrons definition of important quantities - Quantum Mechanics · Electron dynamics in (intense) laser fields · Ionization - High-harmonic generation: quantum mechanical view

  3. Contents Basics of short pulses and general concepts Attosecond pulse generation Mechanics of Electrons single electrons in strong laser fields Attosecond Experiments with isolated Atoms Multi-Particle Systems Molecules multi-electron dynamics (correlation) Attosecond experiments with molecules / multiple electrons Ultrafast Quantum Control of electrons, atoms, molecules Novel Directions/Applications Technology

  4. High Harmonics Quantum Mechanical M. Lewenstein et al. Phys. Rev. Lett. 49, 2117 (1994) 

  5. high-harmonic generation intense laser field acting on single atom probability distribution p(x,y)=|Y(x,y)|2 for the electronic wavefunction laser polarization

  6. Wavepacket spreading

  7. Split-Step Operator Technique

  8. Streak field spectroscopy quantum mechanically, with interference Goulielmakis et al. (Krausz group), Science 305, 1267 (2004)

  9. Streak-field spectroscopy Drescher et al., Nature 419, 803 (2002)

  10. Auger decay in Kr Drescher et al. (Krausz group), Nature 419, 803 (2002)

  11. Tunneling Spectroscopy Uiberacker et al. (Krausz group), Nature 446, 627 (2007)

  12. Tunneling Spectroscopy Uiberacker et al. (Krausz group), Nature 446, 627 (2007)

  13. Strong-Field Physics Experiments Blaga et al. (Paulus, Agostini, DiMauro), Nat. Physics 5, 335 (2009)

  14. Strong-Field Physics Experiments Quan et al. Phys. Rev. Lett. 103, 093001 (2009)

  15. Contents Basics of short pulses and general concepts Attosecond pulse generation Mechanics of Electrons single electrons in strong laser fields Attosecond Experiments with isolated Atoms Multi-Particle Systems Molecules multi-electron dynamics (correlation) Attosecond experiments with molecules / multiple electrons Ultrafast Quantum Control of electrons, atoms, molecules Novel Directions/Applications Technology

  16. Contents Multi-Particle Systems (Molecules, many electrons) Attosecond experiments with molecules / multiple electrons - Molecules and molecular orbitals - Multi-electron Correlation: basics - Born-Oppenheimer and beyond - Recollision physics - Experiments with Molecules

  17. Chemical Bonds http://en.wikipedia.org/wiki/Nitrogen http://www.unige.ch/sciences/Actualites/2007/MaximumMultiplicity/W2_Mutiplicity.png http://ibchem.com/IB/ibfiles/bonding/bon_img/cov2.gif,

  18. Linear Combination of Atomic Orbitals (LCAO) http://www.uweb.ucsb.edu/~jodea/chem1c.htm, http://tannerm.com/images/diatomic7.gif

  19. Molecular electronic structure http://en.wikipedia.org/wiki/File:Benzene_Representations.svg

  20. Complex Molecules http://images.absoluteastronomy.com/images/encyclopediaimages/h/he/hexokinase_ball_and_stick_model,_with_substrates_to_scale_copy.png http://dwb4.unl.edu/Chem/CHEM869K/CHEM869KLinks/www.ccp14.ac.uk/ccp/web-mirrors/llnlrupp/Xray/tutorial/pdb/helix_bonds.gif

  21. Ultrashort x-ray/XUV Pulses and HighHarmonicGeneration >1 nm <1 J ~100 as FreeElectronLasers wavelength ~1.5 Å pulse energy ~1 mJ pulse duration ~1 mm ~20 fs 1 fs (proj.) ~200 m fullycoherent

  22. Complex Molecules every molecule is different! single shot! FreeElectronLasers wavelength ~1.5 Å -2 fs 2 fs 5 fs 10 fs pulse energy ~1 mJ 20 fs 50 fs pulse duration ~20 fs 1 fs (proj.) Neutze et al., Nature 406, 752 (2000)

  23. DNA http://www.chemicalgraphics.com/paul/images/DNA/BallAndStick.jpg

  24. macromopecular dynamics e.g. detach functional group (signaling protein) from enzyme receptor Pictures from: http://www.nfcr.org/Portals/0/Images/3d_blue_green_molecule.jpg, http://hasylab.desy.de/e77/e106/e122/e35842/e35862/Fig1_Hasylab-ultrafast_eng.jpg

  25. Some theory of the chemical bond Valence bond theory Molecular orbital theory localized electronsbetween two atoms delocalized electronswithin entire molecule http://www.york.ac.uk/chemistry/staff/academic/h-n/pkaradakov/ www.jonathanpmiller.com/ become equivalent if extended Born-Oppenheimer always inherently assumed

  26. Complexity of Wavefunctions Hydrogen atom (1 electron, 1 nucleus) can be found analytically everything else: numerics necessary for example: store wavefunctions on a grid 10 points (double precision, 8 B(Bytes)) in each dimension Ground states (and ignoring nuclear core wavefunctions and most nuclear spin states): Hydrogen atom: 16 kB Helium atom: 32 MB Hydrogen molecule: 64 GB Oxygen atom: 21018 GB Methane (16 daltons, [Da]): 6.51034 GB Biomolecule: (kDa-MDa): ~101,000-101,000,000 GB (103(N-1) 2(N-1))8 B - a few ZB (ZettaBytes), 1012 GB is the estimated total data stored digitally estimate by IDC (International Data Corporation) - 50 PB (PetaBytes), 106 GB is estimated information written by mankind in known history

  27. Some theory of the chemical bond Quantum chemistry methods Density Functional Theory (DFT) Hartree-Fock Theory (HF) (single Slater determinant) problems with ground states energetically close to excited states or in bond-breaking situations http://upload.wikimedia.org/wikipedia/en/7/7e/Electron_correlation.png improvements: - Configuration interaction (CI) - Multi-configurational self-consistent field (MCSCF) combination between configuration interaction (where the molecular orbitals are not varied but the expansion of the wave function) and Hartree-Fock (where there is only one determinant but the molecular orbitals are varied). - Semi-empirical quantum chemistry methods for large molecules where other methods fail

  28. Hybridization sp2 http://www.grandinetti.org/Teaching/Chem121/Lectures/Hybridization/

  29. Hybridization sp http://www.grandinetti.org/Teaching/Chem121/Lectures/Hybridization/

  30. Hybridization sp3 http://www.grandinetti.org/Teaching/Chem121/Lectures/Hybridization/

  31. Scientific Goal of AttoPhysics interaction (Coulomb) symmetry (Fermions) Correlation Y( 1, 2) ≠ Ψ( 1) ×Ψ ( 2) e- e- e- e- non-interacting interacting Correlated lectron dynamics e- e- e- (Entanglement) 1 e- location 2 0 location 1 e-

  32. Scientific Goal of AttoPhysics interaction (Coulomb) symmetry (Fermions) Correlation Y( 1, 2) ≠ Ψ( 1) ×Ψ ( 2) e- e- e- e- non-interacting interacting e- location 2 location 1 e- Correlated lectron dynamics e- e- e- any bonding orbital in matter typically occupied by 2 electrons Giant Magnetoresistance High Tc superconductivity e- e- fundamental role in radiation damage (ionization+excitation) importance in life sciences Sept. 2007 Lanzara group, UC Berkeley

  33. Two-electron dynamics Pisharody and JonesScience 303, 813 (2004) – Rydberg electrons – Barium atoms

  34. Quantum Level Spacingsin a molecule Separation: Electronic, Vibrational, Rotational Ytotal=yel,nFvib,mfrot,l Energy Ye,2 Ye,1 5 Ye,0 frot,l Fv,n 0 Internuclear Distance

  35. Born-Oppenheimer Approximation Full Hamiltonian Product Wavefunction: Reduced Hamiltonian (internuclear only) http://www.nat.vu.nl/~wimu/MolPhys.html

  36. Estimation of Quantum Time Scales ħ mpa02 1 2000 L I Molecular rotation frequency =   Tr=300 fs D mp 1 2000 1 50   Molecular vibration frequency    Tv=7 fs D me 1 1    Electron vibration frequency Te=150 as 1 1 ħ mea02 L I Electron rotation frequency =  =

  37. Recollision Physics Paul Corkum, NRC Canada ħ HHG elastic scattering  ATI Strong laser field e- e- e- inelastic scattering  NSDI, excitation, fragmentation spectroscopy parameters: - alignment angle- laser intensity / ellipticity / wavelength / CEP, ... - multicolor excitation - ...

  38. Three-step model P. Corkum, Phys. Rev. Lett. 71, 1994 (1993)

  39. Molecular recollision

  40. HHG ellipticity dependence linear elliptic normalized harmonic yield atom molecule ellipticity A. Flettner et al. (Gerber group) EPJ D (2002)

  41. Argon and Nitrogen static polarizability

  42. Ellipticity experiment setup

  43. Example measurement: H13 in Ar

  44. Experiment and Model: Ar

  45. Nitrogen vs. Argon

  46. HHG-Simulation

  47. Earlier Results

  48. simulation results Ar vs. N2 ellipticity

  49. Electron-Wavepacket ionization propagation recombination 1 Å 3 Å 4 Å different degrees of delocalization -Shaping

  50. Temporal evolution in laser field |(y)|2 |(py)|2 momentum py [a.u.] y coordinate [a.u.] H-Atom 1 Å 3 Å 4 Å y 10 Å x

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