Dynamics of irradiatedclusters and molecules

Solvated molecules

Deposited clusters

Free clusters

ElectronEmission

Laser

Projectile

Irradiation of solvated « bio »molecules- Microscopic mechanisms- Role of water environment- Medical applications- Society applications

Deposited/embedded species- Shaping at nanoscale- Defect formation- Chromophore effects and therapy applications

Laser irradiations of free clusters- Huge energy absorption in intense laser fields- Production of energetic electrons, ions, photons- Many-body « laboratory »- Time resolved dynamics

SpecificationsDynamical descriptionof irradiation and response of - Electrons- Ions - Environment

Implies:

- Variety of systems

- Variety of time scales

- Variety of scenarios

Implies:

- Robustness

- Flexibility

- Modularity

Implies:

- Use of well tested methods

- Simplicity

- Documentation

Example : Na+

9 + laser

I = 5. 1011 W.cm-2 Pulse in cos2

Delay = 50 fsFWHM = 125 fs = 2.3 eV

Laser intensity

0E

Laser polarization

Time Dependent Density Functional Theory (TDDFT)

Ensemble of orbitals (1 electron) / no correlation

One body density

Effective mean field theory (Kohn-Sham)

Explicit ions via pseudo potentials

Detail of structure + ionic Molecular Dynamics (MD)

Ions

Electrons

Kohn-Sham potential Ions + ext.

Local Density Approximation (LDA)

Exch. + Corr. Coulomb direct+ Self Interaction Correction (SIC) …

TDLDA-MD : coupled non adiabatic electrons + ions dynamics

Model (cluster/molecule)

Semi-classical theory available (Vlasov, VUU)

Time Dependent Density Functional Theory (TDDFT)

Ensemble of orbitals (1 electron) / no correlation

One body density

Effective mean field theory (Kohn-Sham)

Explicit ions via pseudo potentials

Detail of structure + ionic Molecular Dynamics (MD)

Ions

Electrons

Kohn-Sham potential Ions + ext.

Local Density Approximation (LDA)

Exch. + Corr. Coulomb direct+ Self Interaction Correction (SIC) …

TDLDA-MD : coupled non adiabatic electrons + ions dynamics

Model (cluster/molecule)

Semi-classical theory available (Vlasov, VUU)

fs

ps

Observables

Optical response : DipoleSpectral analysis Photoabsorption cross sections

Excitation energy

Positions and velocities Kinetic energy, temperature

IonizationTotal number of emitted electronsIonization probabilitiesKinetic energy spectra of electrons (PES)Angular distributions of emitted electrons (PAD)

Ions

Electrons

Electron emission fromirradiated clusters

Las

er (

, I,

, z)

Electron energy

Photoelectrons

Yie

ld( )

d/dE

Ionization

Yie

ld

Photon energy

I

Energy resol. angul. distri.

Electron emission fromirradiated clusters

Las

er (

, I,

, z)

Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

III

Time resolved dynamics

FEL lasers

II

Optical Response

Yie

ld

Electron emission fromirradiated clusters

Las

er (

, I,

, z)

Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

FEL lasers

I

III

Time resolved dynamics

Energy resol. angul. distri.

II

Optical Response

Yie

ld

Exp F

reiburg

Level energy

Exp

Energy resolved angular distributions

Angle-energy correlation

d/ddE

Laser polarization

Exp

. Ros

tock

Angle C60

Theo

PADExp

Theo

Energy resolved angular distributions

Laser polarization

Exp

. Ros

tock

Angle C60

TheoNa58 (no 2d)JelliumOrientation Average

Angle-energy correlation

d/ddE

The orientation Problem…

Exp F

reiburg

Level energy

Exp

PADExp

Theo

Electron emission fromirradiated clusters

Las

er (

, I,

, z)

Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

FEL lasers

I

III

Time resolved dynamics

Energy resol. angul. distri.

II

Optical Response

Yie

ld

FWHM = 20 fs

C2H4

Laser polariz.

Below resonances Resonance region Well above reson.

Ethylene in laser fields

Organic molecule as test case for irradiation with very high frequency lasersComparison to metal clusters (resonance)

Electron emission fromirradiated clusters

Las

er (

, I,

, z)

Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

FEL lasers

I

III

Time resolved dynamics

Energy resol. angul. distri.

II

Optical Response

Yie

ld

Electron emission fromirradiated clusters

Las

er (

, I,

, z)

Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

FEL lasers

I

III

Time resolved dynamics

Energy resol. angul. distri.

II

Optical Response

Yie

ld

Las

er (

, I,

, z)

FEL lasers

II

Electron emission fromirradiated clusters Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

I

III

Time resolved dynamics

Energy resol. angul. distri.

Optical Response

Yie

ld

Las

er (

, I,

, z)

FEL lasers

II

Electron emission fromirradiated clusters Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

I

III

Time resolved dynamics

Energy resol. angul. distri.

Optical Response

Yie

ld

Las

er (

, I,

, z)

FEL lasers

II

Electron emission fromirradiated clusters Photoelectrons

Electron energy

Yie

ld

Angle

Angular distrib.

Yie

ld( ) La

ser

Ionization

Yie

ld

d/dE

d/d

Photon energy

Electron emission fromirradiated clusters

I

III

Time resolved dynamics

Energy resol. angul. distri.

Optical Response

Yie

ld

 Pump – probe for vibration

Strong

Ionization

Weak

Pump

Probe

Mie ~ / R3

Time / Delay

Pla

smon

Mie

/ Io

niz

.

IonizationmapsVibrations

Ionization

Monopole « Pump – Probe »

Dynamics

Ionization as a function of delay between pump and probe laser pulses

Structure (vibrations…)

Dynamics (viscosity…)

Pu

mp

Pro

be

Ionic vibration period

Expansion rate

Exp. Gerber

Irradiation of clusters and molecules

Laser

Projectile

Signals from electrons

Solvated molecules

Deposited clusters

Free clusters

ElectronEmission

Dynamical descriptionof irradiation and response of - electrons- ions- environment

Environment- Hierarchical model Dynamical QM/MM- Na@Ar, Kr, Ne done- Na @ MgO done- Na@H2O in the oven- C, N, O @ H2O in near future- C, N, O @ H2O @Ar in future

Dynamics of ionization in TDDFT- Self Interaction problem (SIC)- Benchmark TDSIC calculation done- Simple approximations in the oven- Dynamical correlations in the future (electronic transport)

Time resolved dynamics- Key importance of non adiabatic electron/ion couplings- Photoelectron spectroscopy energy, angle done/ in the oven- Pump and probe scenarios done- FEL laser domain in the oven- Collisional scenarios in near future- Atto laser domain in the oven

PeopleP. M. Dinh, P. G. Reinhard, ES, Z. Wang

Example of collision : Na+

9 + Ar 8+

E = 2.32 keV b = 20 a0