1. Small fermionic systems : the common methods and challenges
Nuclei
Metal clusters (alkalines) Helium 3 droplets
Structure and Dynamics
Experiments and Theory
J. Navarro (Valencia), P. G. Reinhard (Erlangen), ES (Toulouse)
+ survey (nuclear + He droplets + cluster physicists)

2. Nuclei, Helium, Metals … Atomic Nuclei Helium droplets Metal clusters
Constituents
Fermions
Neutrons,
Protons
3He atoms
(2p, 1n, 2e)
Ions,
Electrons
Nucl.-Nucl.
Van d. Waals
Coulomb
Interactions
Sizes
N < 300
20 < N
3 < N < 105-7
Radius ~ r0,sN1/3
r0 ~ 1fm
rs ~ nm
r0 ~ nm

3. Some common properties
Dense systems
with strong Pauli
Atomic
Nuclei
Helium
droplets
Metal
clusters
 r0,s provides the relevant
length/energy scales
Fermi gas estimate
r = kF3/ (3p2) = 4/(3p r0,s3)
 Inter-constituents distance d ~ r0,s
 Fermi energy eF = h2/2m (3p/4)2/3 1/r0,s2
 Long de Broglie wavelength (ground state)
lB ~ 2p/ kF ~ p r0,s
Quantum mean field

4. Mean-field : a (possible) common theory
Effective mean field theory (1-body : nucleons/electrons/atoms)
Nuclei
TDHF
Density
Functional
Theory
Clusters
Helium
Foundation of extended mean field theories (VUU)

5. From one field to the next …
Nuclei
Structure
Dynamics
Experim.
YES
Theory
Clusters
Structure
Dynamics
Experim.
YES
NO  YES
Theory
Helium
Structure
Dynamics
Experim.
NO  YES NO
Theory
YES
Not yet

6. Multi scale dynamics Nuclei Alkalines (Li, Na, K, Rb, Cs)
 Plasmon (collect. oscill.
electrons/ions)
 Ionic times
 Electron-electron collis.
 Electron evaporation
1 fs
100 fs
10 fs
10 fm/c
1000 fm/c
100 fm/c
Units : microscopic time in rs,0/vF - temperature in eF

7. from irradiated clusters
Electron emission
from irradiated clusters
ds/dE
Electron energy
Photoelectrons
Yield
Laser polarization  
Ionization
Yield
Photon energy
1/ PES: 1-photon then 2-photon processes
2/ ang
3/ Nesc / animation as given + move ions   
Ekin
s ( w )

8. Photoelectron spectra (multiphoton)
ds/dE
Pohl et al, JPB 2004
Exp. Freiburg
w = 0.22 Ry
FWHM = 34 fs 1s 1p w
Electron energy
Photoelectrons
Yield w
 Multiphoton regime
 Evolution with laser intensity ?
 Towards exponential spectra
An exponential spectrum is not necessarily thermal. Caution with temp. HERE: misleading
Check multiphoton regime for Freiburg exp + our calculations / check with PG
Add schem fig. from slide 3 / multiphoton
Role of dissipation ?

9. from irradiated clusters
Electron emission
from irradiated clusters
ds/dE
Photoelectrons
Electron energy
Yield
Laser polarization
ds/dW
Ionization
Yield
Angle
Angular distrib.
Yield
1/ PES: 1-photon then 2-photon processes
2/ ang
3/ Nesc / animation as given + move ions
Photon energy
s ( w )
Laser

10. Angular distributions of photoelectrons
Laser polarization
Laser polar.
Directed emission
Laser Polarization
Na+41
 Intensity
Isotropic emission
Pure mean field:
Directed emission
Mean-field + colls :
Isotropic emission
Exp. W4-, Lyon,2001
Giglio et al, PRA 2003

11. from irradiated clusters
Electron emission
from irradiated clusters
ds/dE
Photoelectrons
Yield
Towards dns/…
d2s/dEdW, d2s/dW1dW2 …
Electron energy
Laser polarization
ds/dW
Ionization
Yield
Angular distrib.
1/ PES: 1-photon then 2-photon processes
2/ ang
3/ Nesc / animation as given + move ions
Yield
Photon energy
Angle
s ( w )
Laser
Laser

12. Some conclusions and perspectives
A few basic questions (inquiry)
1/ Phase transitions in finite systems
(thermodynamics, fragmentation)
See dedicated talk
2/ Density Functional Theory and
Time Dependent DFT,
phenomenological vs microscopic models
Theoretical methods
Many body problem
Experimental methods
Correlations
Multidetetors
3/ Energetic processes (dynamical correlations, Molecular Dynamics)
Theoretical methods
Correlations
Observables
Nuclear towards cluster physics

13. from irradiated clusters
Electron emission
from irradiated clusters
ds/dE
Photoelectrons
Yield
Optical
Response
Yield
Electron energy
Laser polarization
ds/dW
Ionization
Yield
Angular distrib.
1/ PES: 1-photon then 2-photon processes
2/ ang
3/ Nesc / animation as given + move ions
Yield
Photon energy
Angle
s ( w )
Laser
Laser

14. from irradiated clusters
Electron emission
from irradiated clusters
ds/dE
Photoelectrons
Yield
Optical
Response
Yield w
Electron energy w
Laser polarization
ds/dW
Ionization
Yield
Angular distrib.
1/ PES: 1-photon then 2-photon processes
2/ ang
3/ Nesc / animation as given + move ions
Yield
Photon energy
Angle
s ( w )
Laser
Laser

15. from irradiated clusters
Electron emission
from irradiated clusters
ds/dE
Photoelectrons
Yield w
Yield
Optical
Response
Electron energy
Laser polarization
ds/dW
Ionization
Yield
Angular distrib.
1/ PES: 1-photon then 2-photon processes
2/ ang
3/ Nesc / animation as given + move ions
Yield
Photon energy
Angle
s ( w )
Laser
Laser

16. from irradiated clusters
Electron emission
from irradiated clusters
ds/dE
Photoelectrons
Yield w
Yield
Optical
Response
Electron energy
Laser polarization
ds/dW
Ionization
Yield
Angular distrib.
1/ PES: 1-photon then 2-photon processes
2/ ang
3/ Nesc / animation as given + move ions
Yield
Photon energy
Angle
s ( w )
Laser
Laser

17. Pump – probe for fission : principle
Ionization ⃕
/ Ioniz.
high w
2 parameters :
delay
AND
frequency w
Time / Delay
Plasmon
Mie
low w

18. Pump – probe for fission : example
Dinh et al, 2004
Na14 + w  Na143+ hn hn
Na Na82+ hn
Access to fission time
Fission dynamics
Viscosity…