Preface ...................................................... X
List of Contributors ........................................ XI
Colour Plates ............................................... XV
(Aafter page 154)
1 The Electronic Structure of Solids ........................... 1
Uwe Bovensiepen, Silke Biermann, and Luca Perfetti
1.1 Single-Electron Approximation ........................... 2
1.1.1 The Drude Model of the Free Electron Gas ......... 2
1.1.2 The Electronic Band Structure: Metals,
Insulators, and Semiconductors ................... 4
1.2 From Bloch Theory to Band Structure Calculations ........ 6
1.2.1 Bloch Theory ................................... 6
1.2.2 The Tight Binding Approach to the Solid ........ 7
1.2.3 Band Structure Calculations .................... 8
1.3 Beyond the Band Picture ................................. 8
1.3.1 Mott's Hydrogen Solid .......................... 9
1.3.2 Mott Insulators in Nature ..................... 10
1.4 Electronic Structure of Correlated Materials ........... 14
1.4.1 The Hubbard Model ............................. 14
1.4.2 Dynamical Mean Field Theory ................... 16
1.4.3 Electronic Structure Calculations ............. 17
1.4.4 Ordered States ................................ 18
1.4.5 Cooperation Between Lattice Instabilities
and Electronic Correlations: The Example of
Vanadium Dioxide .............................. 21
References .................................................. 23
2 Quasi-Particles and Collective Excitations .................. 27
Evgueni V. Chulkov, Irina Sklyadneva, Mackillo Kira,
Stephan W. Koch, Jose M. Pitarke, Leonid M. Sandratskii,
Paweł Buczek, Kunie Ishioka, Jörg Schäfer, and Martin
Weinelt
2.1 Introduction ........................................... 27
2.2 9uasi-Particles ........................................ 30
2.2.1 Electrons and Holes ............................. 30
2.2.2 Phonons ......................................... 31
2.2.2.1 Adiabatic Approximation ................ 31
2.2.2.2 Harmonie Approximation ................. 31
2.2.2.3 Lattice Dynamics ....................... 32
2.2.2.4 Phonons at Surfaces .................... 33
2.2.3 Electron-Phonon Coupling in Metals .............. 34
2.2.4 Excitons: Electron-Hole Pairs in Semiconductor
Quantum Wells ................................... 38
2.2.4.1 Microscopic Theory ..................... 39
2.2.4.2 Excitonic Resonances and Populations ... 41
2.2.4.3 Terahertz Spectroscopy of Exciton
Populations ............................ 43
2.2.4.4 Excitonic Signatures in the
Photoluminescence ...................... 44
2.2.5 Polarons: Electron-Phonon Coupling in Polar
and Ionic Solids ................................ 46
2.3 Collective Excitations ................................. 49
2.3.1 Plasmons: Electron Density Oscillations ......... 49
2.3.1.1 Surface Plasmons ....................... 51
2.3.1.2 Acoustic Surface Plasmons .............. 52
2.3.2 Magnons: Elementary Excitations in
Ferromagnetic Materials ......................... 53
2.3.2.1 Spin Waves in the Heisenberg Model ..... 54
2.3.2.2 Itinerant Electrons .................... 57
2.3.2.3 Conclusions ............................ 64
2.4 Experimental Access to Quasi-Particle and Collective
Excitations ............................................ 65
2.4.1 Coherent Phonons ................................ 65
2.4.1.1 Coherent Optical Phonons ............... 65
2.4.1.2 Coherent Acoustic Phonons .............. 74
2.4.2 High-Resolution Angle-Resolved Photoemission .... 78
2.4.2.1 Photoemission Spectral Function of
Quasi-Particles ........................ 78
2.4.2.2 Experimental Considerations for
Photoelectron Spectroscopy ............. 80
2.4.2.3 Quasi-Particles from Electron-Phonon
Interaction ............................ 81
2.4.2.4 Quasi-Particles from Electron-Magnon
Interaction ............................ 82
2.4.2.5 Conclusions and Implications ........... 88
2.4.3 Time-Resolved Photoelectron Spectroscopy ........ 89
2.4.3.1 Experiment ............................. 89
2.4.3.2 Electron Lifetimes ..................... 91
2.4.3.3 Electron-Phonon Coupling ............... 94
2.4.3.4 Surface Exciton Formation .............. 97
2.4.3.5 Magnon Emission ....................... 101
2.4.3.6 Magnon-Phonon Interaction ............. 103
2.5 Summary ............................................... 105
References ................................................. 106
3 Surface States and Adsorbate-lnduced Electronic
Structure .................................................. 115
Thomas Fauster, Hrvoje Petek, and Martin Wolf
3.1 Intrinsic Surface States .............................. 115
3.1.1 Basic Concepts of Surface States ............... 115
3.1.2 Scattering Model of Surface States ............. 116
3.2 Crystal-Induced Surface States ........................ 119
3.2.1 Tamm and Shockley Surface States ............... 119
3.2.2 Dangling Bond States ........................... 120
3.3 Barrier-Induced Surface States ........................ 121
3.3.1 Image Potential States ......................... 121
3.3.2 Quantum Well States ............................ 124
3.4 Experimental Methods .................................. 125
3.4.1 Photoemission .................................. 125
3.4.2 Two-Photon Photoemission ....................... 128
3.4.3 Scanning Tunneling Methods ..................... 133
3.5 Adsorbate-Induced Electronic Structure ................ 135
3.5.1 Bonding at Surfaces ............................ 135
3.5.2 Energy-Level Alignment: Alkali-Metal
Interfaces as a Model System ................... 138
3.5.3 Electronic Band Structure: Chemisorbed and
Physisorbed Adsorbates ......................... 147
References ................................................. 151
4 Basic Theory of Heterogeneous Electron Transfer ............ 155
Daniel Sanchez-Portal, Julia Stähler, and Xiaoyang Zhu
4.1 Resonant Charge Transfer in Chemisorbed Systems ....... 155
4.1.1 Anderson-Grimley-Newns Hamiltonian ............. 156
4.1.2 Main Factors that Determine RCT Decay Rates .... 158
4.1.3 Theoretical Approaches to Calculate RCT Rates
in Realistic Systems ........................... 161
4.1.4 Effect of the Adsorbate Motion ................. 163
4.2 Electron Transfer in the Presence of Polar/
Polarizable Media ..................................... 166
4.2.1 Nonadiabatic (Outer Sphere) Electron
Transfer ....................................... 167
4.2.1.1 Continuum of Accepting States ......... 169
4.2.2 Adiabicity and the Effect of Strong
Electronic Coupling ............................ 170
4.2.3 Intermediate Coupling and the Impact of
Solvent Relaxation ............................. 171
4.2.3.1 Classical Description and a Wide
Band Acceptor ......................... 174
4.3 Transient Electronic Coupling: Crossover between
Limiting Cases ........................................ 174
4.4 Conclusions ........................................... 177
References ................................................. 178
5 Electromagnetic Interactions with Solids ................... 181
Ricardo Díez Muiño, Eugene E. Krasovskii, Wolfgang
Schattke, Christoph Lienau, and Hrvoje Petek
5.1 Dielectric Function of Metals ......................... 182
5.1.1 Calculations of Dielectric Functions ........... 183
5.2 Band Mapping of Solids by Photoemission Spectroscopy .. 186
5.2.1 Nonlinear Photoemission as a Band Mapping Tool
for Unoccupied States .......................... 189
5.3 Optical Excitations in Metals ......................... 191
5.3.1 Optical Response of Noble Metals ............... 193
5.3.2 Interband Absorption ........................... 195
5.3.3 Intraband Absorption ........................... 197
5.3.4 Extended Drude Model ........................... 199
5.3.5 Frequency-Dependent Scattering Rate ............ 201
5.3.6 Surface Absorption ............................. 204
5.3.7 Summary ........................................ 206
5.4 Plasmonic Excitations at Surfaces and Nanostructures .. 206
5.4.1 Drude Model for Optical Conductivity ........... 207
5.4.2 Interaction of Light with a Planar Metallic
Surface ........................................ 208
5.4.3 Surface Plasmon Polariton Fields ............... 210
5.4.3.1 Planar Interfaces ..................... 210
5.4.4 Surface Plasmons in Nanostructured Metal
Films .......................................... 215
5.4.4.1 Spherical Nanoparticles ............... 215
5.4.4.2 Elliptical Nanoparticles .............. 219
5.4.4.3 Diffraction Gratings .................. 220
5.4.4.4 Adiabatic Metallic Tapers ............. 224
5.4.5 Exciton-Plasmon Coupling ....................... 227
5.4.6 Summary ........................................ 230
References ................................................. 231
Index ...................................................... 239
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