An Introduction To Cluster Dynamics

Clusters as mesoscopic particles represent an intermediate state of matter between single atoms and solid material. The tendency to miniaturise technical objects requires knowledge about systems which contain a "small" number of atoms or molecules only. This is all the more true for dynamical aspects, particularly in relation to the qick development of laser technology and femtosecond spectroscopy.
Here, for the first time is a highly qualitative introduction to cluster physics. With its emphasis on cluster dynamics, this will be vital to everyone involved in this interdisciplinary subject. The authors cover the dynamics of clusters on a broad level, including recent developments of femtosecond laser spectroscopy on the one hand and time-dependent density functional theory calculations on the other.

Paul-Gerhard Reinhard has been professor for Theoretical Physics at the Friedrich-Alexander university Erlangen/Nürnberg since 1983. He received his PhD in 1970 at the Johann-Wolfgang-Goethe university Frankfurt. His post-doctoral studies brought him to Erlangen, Oxford, and Mainz. He obtained his Habilitation in 1977 at the Johannes-Gutenberg university in Mainz. He was fellow of the Heisenberg program in the years 1978-1983. His present research interests cover cluster physics, nuclear structure physics and plasma physics.

Eric Suraud has been professor for Theoretical Physics at the Paul-Sabatier university in Toulouse, France, since 1992. He received his PhD in 1984 at the Paris university and his Habilitation in 1989 at the Grenoble university. He was junior member of Institut Universitaire de France in 1994-1999. He is presently director of the Institute de Recherche sur les Systemes Atomiques et Moleculaires Complexes in Toulouse and Vice Director of Institut de Physique Nucléaire et des Particules at CNRS in Paris. His present research interests mostly cover cluster physics and nuclear dynamics.

Preface.

1 About clusters.

1.1 Atoms, molecules and solids.

1.1.1 Atoms.

1.1.2 Molecules.

1.1.3 The point of view of solid state physics.

1.2 Clusters between atom and bulk.

1.2.1 Clusters as scalable finite objects.

1.2.2 Varying cluster material.

1.3 Metal clusters.

1.3.1 Some specific properties.

1.3.2 On time scales.

1.3.3 Optical properties.

1.4 Conclusion.

2 From clusters to numbers: experimental aspects.

2.1 Production of clusters.

2.1.1 Cluster production in supersonic jets: a telling example.

2.1.2 More cluster sources.

2.1.3 Which clusters for which physics.

2.2 Basic experimental tools.

2.2.1 Mass spectrometers.

2.2.2 Optical spectroscopy.

2.2.3 Photoelectron spectroscopy.

2.3 Examples of measurements.

2.3.1 Abundances.

2.3.2 Ionization potentials.

2.3.3 Static polarizabilities.

2.3.4 Optical response.

2.3.5 Vibrational spectra.

2.3.6 Conductivity.

2.3.7 Magnetic moments.

2.3.8 Photoelectron spectroscopy.

2.3.9 Heat capacity.

2.3.10 Dissociation energies.

2.3.11 Limit of stability.

2.3.12 Femtosecond spectroscopy.

2.4 Conclusion.

3 The cluster many-body problem: a theoretical perspective.

3.1 Ions and electrons.

3.1.1 An example of true cluster dynamics.

3.1.2 The full many-body problem.

3.1.3 Approximations for the ions as such.

3.2 Approximation chain for the ion–electron coupling.

3.2.1 Core and valence electrons.

3.2.2 Pseudo-potentials.

3.2.3 Jellium approach to the ionic background.

3.3 Approximation chain for electrons.

3.3.1 Exact calculations.

3.3.2 Ab initio approaches.

3.3.3 Density-functional theory.

3.3.4 Phenomenological electronic shell models.

3.3.5 Semiclassical approaches.

3.4 Putting things together.

3.4.1 Coupled ionic and electronic dynamics.

3.4.2 Born-Oppenheimer MD.

3.4.3 Structure optimization.

3.4.4 Modeling interfaces.

3.4.5 Approaches eliminating the electrons.

3.5 Conclusions.

4 Gross properties and trends.

4.1 Observables.

4.1.1 Excitation mechanisms.

4.1.2 Energies.

4.1.3 Shapes.

4.1.4 Emission.

4.1.5 Polarizability.

4.1.6 Conductivity.

4.1.7 Spectral analysis.

4.2 Structure.

4.2.1 Shells.

4.2.2 Shapes.

4.3 Optical response.

4.3.1 Mie plasmon, basic trends.

4.3.2 Basic features of the plasmon resonance.

4.3.3 Effects of deformation.

4.3.4 Other materials.

4.3.5 Widths.

4.4 Metal clusters and nuclei.

4.4.1 Bulk properties.

4.4.2 Shell effects.

4.4.3 Collective response.

4.4.4 Fission.

4.4.5 Cluster versus nuclear time scales.

4.5 Conclusions.

5 New frontiers in cluster dynamics.

5.1 Structure.

5.1.1 Fractal growth.

5.1.2 Hedroplets.

5.1.3 Heat capacity.

5.1.4 Static polarizability.

5.1.5 Magnetic properties.

5.2 Observables from linear response.

5.2.1 Optical absorption.

5.2.2 Beyond dipole modes.

5.2.3 Photoelectron spectroscopy.

5.3 Laser excitations in the semi-linear regime.

5.3.1 Electron emission.

5.3.2 Shaping clusters.

5.3.3 Ionic effects in laser pulses of varied length.

5.3.4 Pump and probe analysis.

5.4 Excitation by particle impact.

5.4.1 Stability of clusters.

5.4.2 Collisions with ions.

5.4.3 Collisions with neutral atoms.

5.4.4 Electron scattering.

5.5 Strongly non-linear laser processes.

5.5.1 Signals from exploding clusters.

5.5.2 Modeling exploding clusters.

5.5.3 Nuclear reactions.

5.6 Conclusion.

6 Concluding remarks.

Appendix.

A Conventions of notations, symbols, units, acronyms.

A.1 Units.

A.2 Notations.

A.3 Acronyms.

A.4 A few reference books on cluster physics and related domains.

B Gross properties of atoms and solids.

B.1 The periodic table of elements.

B.2 Atomic trends.

B.3 Electronic structure of atoms.

B.4 Properties of bulk material.

C Some details on basic techniques from molecular physics and quantum chemistry.

C.1 The Born-Oppenheimer approximation.

C.2 Ab initio methods for the electronic problem.

C.2.1 Hartree Fock as a starting point.

C.2.2 Beyond HF: CI and MCHF/MCSCF.

D More on pseudo-potentials.

D.1 Construction of norm conserving pseudo-potentials.

D.2 Ultra soft pseudo-potentials.

D.3 Examples of simple local pseudo-potentials.

E More on density functional theory.

E.1 Kohn-Sham equations with spin densities.

E.2 Gradient corrections in LDA.

E.3 Self interaction correction.

E.4 Time-dependent LDA and beyond

F Fermi gas model and semi-classics.

F.1 TheFermi gas.

F.2 Infinite electrongas atHartree-Fock level.

F.3 The Thomas-Fermi approach.

F.4 Details of the nano-plasma model.

G Linearized TDLDA and related approaches.

G.1 The linearized equations.

G.2 Sumrule approximation.

H Numerical considerations.

H.1 Representation of electron wave functions and densities.

H.2 Iteration and propagation schemes.

H.2.1 Electronic ground state.

H.2.2 Dynamics.

H.3 Detailson simulatedannealing.

H.4 The test-particlemethodforVlasov-LDAandVUU.

H.5 On the solution of theTDTFequation.

Bibliography.

Index.