Probing Molecular Electronic Structure Using High Harmonic Generation Tomography

50 %
50 %
Information about Probing Molecular Electronic Structure Using High Harmonic Generation...
Technology

Published on December 2, 2013

Author: ChelseyCrosse

Source: slideshare.net

Description

The structure of valence electronic orbitals of a molecule determines the majority of chemical properties. Generation of high-order harmonic frequencies from atomic sources has been directly related to the electronic structure of the atom, (1) and extended as far as tomographic reconstruction of linearly symmetric polyatomic molecular systems with some success. (2,3,4)

However, because of the increased resolution of these reconstructions, discrimination of fine details of the orbital reconstructions reveals some inconsistencies in the orbital shapes when compared with past models & theoretical calculations. (2) There are several proposed corrections to the Strong Field Approximation (SFA) that currently underlies tomographic reconstruction as well as all other experiments that use high harmonic generation (HHG) to probe molecular systems. (5,6,7)
---------------------------------------------------------------------
1. Lewenstein et al. Phys Rev A 49 (3) 1994.
2. Salieres, Maquet, Haessler, Caillat, Taieb. Rep. Prog. Phys. 75 (2012) 062401.
3. Li, Liu, Yang, Song, Zhao, Lu, Li, Xu. Opt. Ex. 21 (6) 2013. 7599.
4. Torres et al. Phys Rev. Lett. 98 (2007) 203007.
5. Diveki et. al. J. Chem Phys. 414 (2013) 121.
6. Yip, Palacios, Rescigno, McCurdy, Martin. J. Chem Phys 414 (2013) 112.
7. Spanner, Patchkovskii. J. Chem. Phys. 414 (2013) 10.

PROBING MOLECULAR ELECTRONIC STRUCTURE USING HIGH HARMONIC GENERATION TOMOGRAPHY CHELSEY CROSSE LEVINGER GROUP | COLORADO STATE UNIVERSITY LITERATURE SEMINAR | OCTOBER 23, 2013

MOLECULAR ELECTRONIC STRUCTURE Geometry Chang. Chemistry, 8th ed.; McGraw-Hill:New York, 2005. Benzene Reactions, Tutorvista. chemistry.tutorvista.com/ (accessed 11 Oct. 2013). Han, Choi, Kumar & Stanley. Nature Physics. 2010, 6, 633. Phase Behavior 1 Bonding

Hydrogenic Orbitals Molecular Orbitals Siriwardane. CHEM 281, LA Tech. www.chem.latech.edu (accessed 11 Oct. 2013). N2 HOMO Highest Occupied Molecular Orbital 2 MOLECULAR ORBITALS OF NITROGEN

EXPERIMENTAL METHODS OF MEASURING MOLECULAR STRUCTURE de Oteyza et al. Science. 2013, 340, 1434. 3 3Å

MEASUREMENT REQUIREMENTS FOR ORBITAL TOMOGRAPHY 1. Observable • High Harmonic Generation (HHG) radiation 2. Selective Tunneling probability • Molecular alignment 4 •

OVERVIEW OF HIGH HARMONIC GENERATION TOMOGRAPHY Diveki et al. Chemical Physics, 2013, 414, 121. ”High Harmonic Generation” Wikipedia. en.wikipedia.org (accessed 18 Oct. 2013). 5 “A MOLECULE BEING PROBED BY ONE OF ITS OWN ELECTRONS”

HARMONIC GENERATION IN A GAS JET • • • Odd order harmonics Linear trend Multi-photon Ionization followed by electron relaxation. Low Intensity (I ≤1013 W/cm2) Number of photons • Classical Harmonic Generation: Harmonic order (n) • Plateau followed by linear decrease DIFFERENT PHYSICAL MECHANISM New & Ward. Physical Review Letters. 1967, 19, 556. Hecht, J. “Photonic Frontiers: High Harmonic Generation,” LaserFocusWorld 2012. Harmonic order (n) 6 • Number of photons • High Harmonic Generation (HHG) High Intensity ( I ≥1014 W/cm2)

Probe Torres et. al. Physical Review Letters. 2007, 98, 203007. Alignment: ~100 fs Ti:Sapph @ 808 nm, I ≤ 1013 W/cm2 Probe: ~15 fs Ti:Sapph, I ~1014 W/cm2 Alignment 7 EXPERIMENTAL SETUP

SEMI-CLASSICAL THREE STEP MODEL 1. Tunneling (Quantum Mechanical) 2. Acceleration of Electron in Laser Field (Classical) 3. Recombination (Quantum Mechanical) 0t =0 Elaser = 0 0t ~ /2 Elaser Lewenstein et al. Physical Review A. 1994, 49, 2117. Mahieu Seminar at UNG 2009. 3. 2. 0t = Elaser = 0 0t ~ 3 /2 Elaser 0t =2 Elaser = 0 8 1.

SEMI-CLASSICAL THREE STEP MODEL 0t =0 Elaser = 0 Energy Ground state (SCHEMATIC) EI 0 Distance from Molecular Center of Mass Mahieu Seminar at UNG 2009. 9 e-

SEMI-CLASSICAL THREE STEP MODEL 0t ~ /2 Elaser 0t = Elaser =0 Energy 1. Tunneling (Quantum Mechanical) 0 Distance from Molecular Center of Mass Mahieu Seminar at UNG 2009. 10 e-

1. Observable • HHG radiation Energy MEASUREMENT REQUIREMENTS FOR ORBITAL TOMOGRAPHY 2. Selective Tunneling probability • Molecular alignment e- 0 Distance from Molecular Center of Mass 11 

SEMI-CLASSICAL THREE STEP MODEL 0t ~ /2 Elaser 0t ~ 3 /2 Elaser 2. Acceleration of Free Electron in Laser Field (Classical) 0 Distance from Molecular Center of Mass Mahieu Seminar at UNG 2009. 12 Energy e-

SEMI-CLASSICAL THREE STEP MODEL 0t =0 Elaser = 0 3. Recombination (Quantum Mechanical) 0 Distance from Molecular Center of Mass Mahieu Seminar at UNG 2009. 13 Energy e-

1. Observable  HHG radiation Energy MEASUREMENT REQUIREMENTS FOR ORBITAL TOMOGRAPHY 2. Selective Tunneling probability • Molecular alignment e- 0 Distance from Molecular Center of Mass 14 

THREE STEP MODEL RELATES TO RADIATION   f  I HHG µ g (k, I L , q )a(k, I L )d (k, q ) q IL  k 1. Tunneling (Quantum Mechanical)  g (k, I L ,q ) • Tunneling probability 2. Acceleration of Electron in Laser Field (Classical)  • a(k, I L ) 3. Recombination (Quantum Mechanical) •   f ˆ d (k,q ) = <y0 (q ) | d | yc (k)> f Acceleration Transition dipole Diveki et al. Chemical Physics, 2013, 414, 121. 15 matrix

CALIBRATION OF MEASUREMENTS • •   f  I HHG µ g (k, I L , q )a(k, I L )d (k, q )  Function of laser characteristics a(k, I L )  g (k, I L ,q ) Function of ionization potential Given observation of a reference system:  f  1 I(w, I L , q )  f  ˆ <y0 (q ) | d | yc (k)> = d (k, q ) µ dref (k ) R(q ) I ref (w, I L ) f Diveki et al. Chemical Physics, 2013, 414, 121. 16 ANGULAR DEPENDENCE

Smith. The Scientist & Engineer's Guide to Digital Signal Processing. California Technical Publishing 1997. www.dspguide.com (accessed 16 Oct. 2013). 17 TOMOGRAPHY INTERLUDE: COMPUTED TOMOGRAPHY

Smith. The Scientist & Engineer's Guide to Digital Signal Processing. California Technical Publishing 1997. www.dspguide.com (accessed 16 Oct. 2013). 18 TOMOGRAPHY INTERLUDE: COMPUTED TOMOGRAPHY

ab initio HOMO res et. al. Chemical Physics. 2013, 414, 121. N2 HOMO HHG Tomography HOMO 19 MOLECULAR TOMOGRAPHY

MOLECULAR ALIGNMENT • Molecular Sample • T ~ 100 K • Initial alignment: • • • • ~100 fs pulse I ~ 1013 W/cm2 Induces rotational wave packet NON-ADIABATIC • Rotational Revival • ~70% rotational realignment Distinguishable within 5° at 100K Lock et al. Physical Review Letters. 2012, 108, 133901. 20 •

MEASUREMENT REQUIREMENTS FOR ORBITAL TOMOGRAPHY 1. Observable  HHG radiation 2. Selective Tunneling probability  Molecular alignment 21 

N2 HOMO Itatani et. al. Nature. 2004, 432, 867. 22 THEORETICAL EXPERIMENTAL HHG TOMOGRAPHY DATA: N2

THE STRONG FIELD APPROXIMATION Assumptions:  • Born-Oppenheimer approximation  • Hartree-Fock approximation  • Koopman’s approximation • Free electron is a plane wave • Single active electron • Neglect the Stark effect • Neglect relativity Diveki et al. Chemical Physics, 2013, 414, 121. Spanner, Patchkovskii. Chemical Physics 2013, 414 10. 23 • Neglect Coulombic interaction

CONTINUUM WAVEFUNCTIONS N2 HOMO Dyson Orbital for N2 Ionization: ydj = n < I j | N > Spanner, Patchkovskii. Chemical Physics 2013, 414 10. 24 Modeled < yc |

CONTINUUM WAVEFUNCTIONS Dyson Orbital for CO2 Ionization Spanner, Patchkovskii. Chemical Physics 2013, 414 10. 25 Modeled < yc |

THE STRONG FIELD APPROXIMATION Assumptions:  Born-Oppenheimer approximation  Hartree-Fock approximation  Koopman’s approximation o Free electron is a plane wave • Single active electron • Neglect the Stark effect • Neglect relativity Diveki et al. Chemical Physics, 2013, 414, 121. Spanner, Patchkovskii. Chemical Physics 2013, 414 10. 26 • Neglect Coulombic interaction

MULTIPLE ACTIVE ELECTRONS THEORETICAL SINGLE ACTIVE ELECTRON Itatani et. al. Nature. 2004, 432, 867. Patchkovskii, Zhao, Brabec, Villeneuve. Physical Review Letters. 2006, 97, 12003. 27 MULTIPLE ACTIVE ELECTRONS

THE STRONG FIELD APPROXIMATION Assumptions:  Born-Oppenheimer approximation  Hartree-Fock approximation  Koopman’s approximation o Free electron is a plane wave o Single active electron • Neglect the Stark effect • Neglect relativity Diveki et al. Chemical Physics, 2013, 414, 121. Spanner, Patchkovskii. Chemical Physics 2013, 414 10. 28 • Neglect Coulombic interaction

N2 HOMO Patchkovskii, Zhao, Brabec, Villeneuve. Physical Review Letters. 2006, 97, 12003. 29 THEORETICAL MULTI ACTIVE ELECTRONS REMAINING DISTORTIONS

FUTURE GOAL: POLYATOMIC MOLECULES CHALLENGES: • Closer energy spacing • Complex free electron wavefunctions Siriwardane. CHEM 281, LA Tech. www.chem.latech.edu (accessed 11 Oct. 2013). 30 • Smaller molecular dipoles

FUTURE GOAL: POLYATOMIC MOLECULES CHALLENGES: • Closer energy spacing • Complex free electron wavefunctions Dyson Orbital for Modeled < yc | Corenene Ionization for Corenene Spanner, Patchkovskii. Chemical Physics 2013, 414 10. 31 • Smaller molecular dipoles

FUTURE GOAL: POLYATOMIC MOLECULES CHALLENGES: • Closer energy spacing • Complex free electron wavefunctions Acetylene Allene Torres et. al. Physical Review Letters. 2007, 98, 203007. 32 • Possibility of smaller torque

•  Physical mechanism •  Some agreement EXPERIMENTAL MULTI ACTIVE ELECTRONS SUMMARY •  Polyatomic systems Spanner, al. Nature. 2004, 432, 867. Itatani et. Patchkovskii. Chemical Physics 2013, 414 10. ”High Harmonic Generation” Wikipedia. en.wikipedia.org (accessed 18 Oct. 2013). Patchkovskii, Zhao, Brabec, Villeneuve. Physical Review Letters. 2006, 97, 12003. Modeled < yc | for Corenene 33 Remaining Distortions THEORETICAL THEORETICAL •  Revisions &

ACKNOWLEDGEMENTS Levinger Group: • Dr. Nancy Levinger • Ben Wiebenga-Sanford CSU Department of Chemistry PEERS Chemistry: Faculty: • Dr. Elliot Bernstein • Dr. Mario Marconi • Dr. Carmen Menoni Laura Tvedte, Jenée Cyran, Jake Nite, Kathryn Tracy Electrical & Computer Engineering: • Dr. Randy Bartels Reed Hollinger, Clayton Bargsten, Drew Schiltz Communication: Post-Doctorates & Staff Scientists: Vicky Webber Materials Science: • Dr. Amber Krummel • Dr. Brad Luther Katherine Sebeck 34 • Dr. Christopher Rich

MULTIPLE ACTIVE ELECTRONS N2 HOMO HOMO res et. al. Chemical Physics. 2013, 414, 121. HOMO-1 B-1 THEORETICAL – Hartree-Fock

THEORETICAL H-F HOMO res et. al. Chemical Physics. 2013, 414, 121. N2 HOMO EXPERIMENTAL Harmonics 17-31 B-3 MULTIPLE ACTIVE ELECTRONS

THEORETICAL H-F HOMO-1 res et. al. Chemical Physics. 2013, 414, 121. N2 HOMO EXPERIMENTAL Harmonics 17-31 B-3 MULTIPLE ACTIVE ELECTRONS

MULTI-ACTIVE ELECTRONS res et al Chemical Physics 414 (2013) 121–129 IL = 1.0x1014 W/cm2 B-4 IL = 1.2x1014 W/cm2

RECONSTRUCTION Inverse Fourier transform of the recombination dipole moment yields: res et al Chemical Physics 414 (2013) 121–129 C u = x ', z'   1 D(w, I L , q )  f  ˆ r du (k ) =< y 0 | u | k >= dref (k ) R(q ) Dref (w, I L )  rˆ Á ® r '[du (kx ', kz ' )] u y0 (x ', z') = k u

HHG TOMOGRAPHY DATA: N2 0° Itatani et. al. Nature. 2004, 432, 867. D HHG Tomography HOMO

ELECTRON TRAJECTORY Electron position x x(ti)=0 v(ti)=0 1 0 21 19 17 15 0 Mairesse et al. Science 302, 1540 (2003) Kazamias and Balcou, PRA 69, 063416 (2004) Short traj. Chirp > 0 Long traj. Chirp < 0 Emission time (te) E Harmonic order Time (TL)

Add a comment

Related presentations

Presentación que realice en el Evento Nacional de Gobierno Abierto, realizado los ...

In this presentation we will describe our experience developing with a highly dyna...

Presentation to the LITA Forum 7th November 2014 Albuquerque, NM

Un recorrido por los cambios que nos generará el wearabletech en el futuro

Um paralelo entre as novidades & mercado em Wearable Computing e Tecnologias Assis...

Microsoft finally joins the smartwatch and fitness tracker game by introducing the...

Related pages

Probing Electronic Structures Using High Harmonic ...

Probing Electronic Structures Using High Harmonic Generation Tomography ... molecular electronic structure ... high harmonic generation (HHG) tomography ...
Read more

www.science.gov

www.science.gov
Read more

Self-probing of molecules with high harmonic generation ...

... generation and molecular orbital tomography in ... of electronic structure from high harmonic ... molecular high harmonic generation using a ...
Read more

Probing the electronic structure of molecules with high ...

Probing the electronic structure of molecules ... that high harmonic generation in aligned ... Coherent Molecular Rotations by High Harmonic ...
Read more

Core-polarization effects in molecular high harmonic ...

Core-polarization effects in molecular high harmonic generation. ... of electronic structure from the harmonic ... probing of molecules with high harmonic ...
Read more

High-order harmonic generation and applications to ...

High-order harmonic generation and ... outermost electronic structure (molecular orbital) ... Molecular orbital tomography .
Read more

Probing molecular chirality on a sub-femtosecond timescale ...

High-harmonic generation can ... Probing molecular ... The strength of the chiral-sensitive sub-cycle transitions depends on the electronic structure ...
Read more

Attosecond imaging of molecular electronic wavepackets ...

High-order harmonic generation ... Probing molecular dynamics with attosecond resolution using ... General atomic and molecular electronic-structure ...
Read more

molecular orbital tomography - arxiv.org

... “High harmonic generation and molecular ... “Attosecond imaging of molecular electronic ... “Molecular orbital tomography using ...
Read more