Scanning Tunneling Microscopy III provides a unique introduction to the theoretical foundations of scanning tunneling microscopy and related scanning probe methods. The different theoretical concepts developed in the past are outlined, and the implications of the theoretical results for the interpretation of experimental data are discussed in detail. Therefore, this book serves as a most useful guide for experimentalists as well as for theoreticians working in the filed of local probe methods. In this second edition the text has been updated and new methods are discussed.

Inhalt

1. Introduction.- 1.1 Theoretical Concepts for Scanning Tunneling Microscopy.- 1.2 Theoretical Concepts for Force Microscopy.- References.- 2. STM Imaging of Single-Atom Adsorbates on Metals.- 2.1 Tunneling Hamiltonian Approach.- 2.2 Adsorbates on Metal Surfaces.- 2.2.1 Topography.- 2.2.2 Spectroscopy.- 2.2.3 Voltage Dependence of Images - Apparent Size of an Adatom.- 2.3 Close Approach of the Tip: The Strong-Coupling Regime.- 2.3.1 From Tunneling to Point Contact.- 2.3.2 Measuring the Tunneling Barrier.- References.- 3. The Scattering Theoretical Approach to the Scanning Tunneling Microscope.- 3.1 The Theoretical Formalism.- 3.1.1 The Limits of Perturbation Theory.- 3.1.2 Tunneling as a Scattering Process.- 3.1.3 Current Density and Generalized Ehrenfest Theorem.- 3.1.4 Local Charge Density at the Fermi Level and Tunnel Current.- 3.1.5 Resonance Tunneling.- 3.2 Tunneling Through Thick Organic Layers.- 3.2.1 The Experimental Situation.- 3.2.2 A Simple Soluble Model.- 3.3 Scanning Tunneling Microscopy at Metal Surface.- 3.3.1 A Method Based on the Korringa-Kohn-Rostocker (KKR) Band Theory.- 3.3.2 Including the Atomic Structure of the Tip: Model Hamiltonian Approach.- 3.3.3 Close Packed Metal Surface.- 3.3.4 Open Metal Surfaces.- 3.3.5 Imaging Adsorbed Alkali Atoms: K/Cu(110).- 3.4 Summary and Conclusions.- References.- 4. Spectroscopic Information in Scanning Tunneling Microscopy.- 4.1 Green's Function Method.- 4.1.1 Matching at a Single Surface.- 4.1.2 Matching at Two Surfaces.- 4.2 Derivation of the Transfer Hamiltonian Approach.- 4.2.1 The Transfer Hamiltonian Approach.- 4.2.2 Tersoff and Hamann's Theory.- 4.2.3 New Derivation of the Transfer Hamiltonian Approach.- 4.2.4 Validity of the Transfer Hamiltonian Approach.- 4.3 One-Dimensional Models.- 4.3.1 Free Electron Model with a Square Barrier.- 4.3.2 One-Dimensional Array of Square Well Potentials.- 4.3.3 The Question of the Surface States.- 4.3.4 Resonant States in the Barrier.- 4.4 Three-Dimensional Models.- 4.4.1 Formalism for a Spherical Tip.- 4.4.2 Application to an Adsorbate on a Surface.- 4.5 Conclusion.- References.- 5. The Role of Tip Atomic and Electronic Structure in Scanning Tunneling Microscopy and Spectroscopy.- 5.1 Background.- 5.2 Formalism of Theoretical Simulation of STM/STS.- 5.3 Simulation of STM/STS of the Graphite Surface.- 5.3.1 Normal Images.- 5.3.2 Abnormal Images.- 5.3.3 Effect of the Atom Kind of the Tip and the Tunnel Current Distribution.- 5.4 STM/STS of Si(100) Reconstructed Surfaces.- 5.5 The Negative-Differential Resistance Observed on the Si(111)$$ \sqrt {3} $$ × $$ \sqrt {3} $$-B Surface.- 5.6 The STM Image of the Si(111)$$ \sqrt {3} $$ × $$ \sqrt {3} $$-Ag Surface and the Effect of the Tip.- 5.7 Light Emission from a Scanning Tunneling Microscope.- 5.8 Summary and Future Problems.- Note Added in Proof.- References.- 6. Bohm Trajectories and the Tunneling Time Problem.- 6.1 Background.- 6.1.1 Motivation.- 6.1.2 Defining the Problem.- 6.2 A Brief Discussion of Previous Approaches.- 6.3 Bohm's Trajectory Interpretation of Quantum Mechanics.- 6.3.1 A Brief Introduction.- 6.3.2 Transmission and Reflection Times Within Bohm's Interpretation.- 6.4 Application to Simple Systems.- 6.4.1 Some Numerical Details.- 6.4.2 Reflection Times for an Infinite Barrier.- 6.4.3 Transmission and Reflection Times for Rectangular Barriers.- 6.4.4 Coherent Two-Component Incident Wave Packet.- 6.4.5 Transmission Times for Time-Modulated Barriers.- 6.4.6 Transmission Times for Symmetric Double Rectangular Barriers.- 6.5 Discussion.- 6.5.1 'Measurement' of Particle Momentum.- 6.5.2 'Measurement' of Mean Transmission and Reflection Times.- 6.5.3 Concluding Remarks.- References.- Additional References with Titles.- 7. Unified Perturbation Theory for STM and SFM.- 7.1 Background.- 7.1.1 A Brief Summary of Experimental Facts.- 7.1.2 The Bardeen Approach for Tunneling Phenomena.- 7.1.3 Perturbation Approach for STM and SFM.- 7.2 The Modified Bardeen Approach.- 7.2.1 General Derivation.- 7.2.2 The Square-Barrier Problem.- 7.2.3 The Hydrogen Molecular Ion.- 7.2.4 The Tunneling Time.- 7.2.5 Asymptotic Accuracy of the Bardeen Tunneling Theory.- 7.2.6 Tunneling Conductance and Attractive Atomic Force.- 7.3 Explicit Expressions for Tunneling Matrix Elements.- 7.4 Theoretical STM Images.- 7.4.1 The Method of Leading Bloch Waves.- 7.4.2 The Method of Independent Atomic Orbitals.- 7.5 Effect of Atomic Forces in STM Imaging.- 7.5.1 Stability of STM at Short Distances.- 7.5.2 Effect of Force in Tunneling Barrier Measurements.- 7.6 In-Situ Characterization of Tip Electronic Structure.- 7.7 Summary.- 7.8 Appendix: Modified Bardeen Integral for the Hydrogen Molecular Ion.- References.- 8. Theory of Tip-Sample Interactions.- 8.1 Tip-Sample Interaction.- 8.2 Long-Range (Van der Waals) Forces.- 8.3 Interaction Energy: Adhesion.- 8.4 Short-Range Forces.- 8.5 Deformations.- 8.6 Atom Transfer.- 8.7 Tip-Induced Modifications of Electronic Structure.- 8.8 Calculation of Current at Small Separation.- 8.9 Constriction Effect.- 8.10 Transition from Tunneling to Ballistic Transport.- 8.11 Tip Force and Conductivity.- 8.12 Summary.- References.- 9. Consequences of Tip-Sample Interactions.- 9.1 Methodology.- 9.2 Case Studies.- 9.2.1 Clean Nickel Tip/Gold Surface.- 9.2.2 Gold-Covered Nickel Tip/Gold Surface.- 9.2.3 Clean Gold Tip/Nickel Surface.- 9.2.4 Nickel Tip/Hexadecane Film/Gold Surface.- 9.2.5 CaF2 Tip/CaF2 Surface.- 9.2.6 Silicon Tip/Silicon Surface.- References.- 10. Theory of Contact Force Microscopy on Elastic Media.- 10.1 Description of a Scanning Force Microscope.- 10.2 Elastic Properties of Surfaces.- 10.2.1 Continuum Elasticity Theory for Layered Materials.- 10.2.2Atomic Theory.- 10.3 Interaction Between SFM and Elastic Media.- 10.3.1 Local Flexural Rigidity.- 10.4 Conclusions and Outlook.- References.- 11. Theory of Atomic-Scale Friction.- 11.1 Microscopic Origins of Friction.- 11.2 Ideal Friction Machines.- 11.2.1 Sliding Friction.- 11.2.2 Rolling Friction.- 11.3 Predictive Calculations of the Friction Force.- 11.3.1 Tip-Substrate Interactions in Realistic Systems: Pd on Graphite.- 11.3.2 Atomic-Scale Friction in Realistic Systems: Pd on Graphite.- 11.4 Limits of Non-destructive Tip-Substrate Interactions in Scanning Force Microscopy.- References.- 12. Theory of Non-contact Force Microscopy.- 12.1 Methodical Outline.- 12.2 Van der Waals Forces.- 12.2.1General Description of the Phenomenon.- 12.2.2 The Two-Slab Problem: Separation of Geometrical and Material Properties.- 12.2.3 Transition to Renormalized Molecular Interactions.- 12.2.4 The Effect of Probe Geometry.- 12.2.5 Dielectric Contributions: The Hamaker Constants.- 12.2.6 On the Observability of Van der Waals Forces.- 12.2.7 The Effect of Adsorbed Surface Layers.- 12.2.8 Size, Shape, and Surface Effects: Limitations of the Theory.- 12.2.9 Application of Van der Waals Forces to Molecular-Scale Analysis and Surface Manipulation.- 12.2.10 Some Concluding Remarks.- 12.3 Ionic Forces.- 12.3.1 Probe-Sample Charging in Ambient Liquids.- 12.3.2 The Effect of an Electrolyte Solution.- 12.4 Squeezing of Individual Molecules: Solvation Forces.- 12.5 Capillary Forces.- 12.6 Conclusions.- References.- 13. Recent Developments.- 13.1 STM Imaging of Single-Atom Adsorbates on Metals.- 13.2 The Scattering Theoretical Approach to Scanning Tunneling Microscopy and Scanning Tunneli…