Photoelectron Spectroscopy: Bulk and Surface Electronic Structures

Description

Preface Acknowledgements Contents About the Authors Acronyms Symbols 1 Introduction References 2 Theoretical Background 2.1 Photoemission Process as One of the Optical Processes 2.2 Three-Step Model 2.2.1 Introduction of Three-Step Model 2.2.2 Step-1: Photoexitations in Solids 2.2.3 Step-2: Travel of Photoelectrons to the Surface 2.2.4 Step-3: Emission of Photoelectrons into the Vacuum 2.3 Matrix Element Effects 2.3.1 Momentum Conservation Law for Valence-Band Excitations 2.3.2 Photoionization Cross-Sections (PICS) 2.3.3 Photoelectron Angular Distribution and Polarization Dependence 2.3.4 Polarization Dependence in Angle-Resolved Photoemission 2.3.5 Other Remarks 2.4 Valence-Band Photoexcitation Process for Non-interacting Systems 2.4.1 Koopmans' Theorem 2.4.2 Formulation of Angle-Integrated Photoemission for Non-interacting Systems 2.4.3 Formulation of Angle-Resolved Photoemission for Non-interacting Systems 2.5 Valence-Band Photoexcitation Process for Strongly Correlated Electrons Systems 2.5.1 Effects of Coulomb Repulsions 2.5.2 Formulations of ARPES Spectra of Strongly Correlated Electron Systems 2.5.3 Quasiparticles and Incoherent Part in the PES Spectra 2.5.4 Energy Scale of the Self-energy 2.6 Core-Level Photoexcitation Process for Strongly Correlated Electrons Systems 2.6.1 Core-Level PES Spectra Reflecting the Outer Strongly Correlated Electronic States 2.6.2 Formulations of Core-Level PES 2.6.3 Intra-atomic Multiplet Structure in the Core-Level PES Spectra 2.7 Theoretical Models to Describe the Spectra of Strongly Correlated Electron Systems 2.7.1 Overview 2.7.2 Periodic Anderson Model (PAM) and d-p Model 2.7.3 Single Impurity Anderson Model 2.7.4 Configuration-Interaction Cluster Model 2.7.5 Hubbard Model 2.7.6 Dynamical Mean Field Theory 2.7.7 Some Remarks References 3 Instrumentation and Methodology 3.1 Synchrotron Radiation and Undulator Radiation 3.2 Principle of Grating and Crystal Monochromators 3.2.1 Grating Monochromators 3.2.2 Crystal Monochromators 3.2.3 Focusing Mirrors 3.3 Examples of Light Sources 3.3.1 High Resolution Vacuum Ultraviolet Synchrotron Radiation Beam Lines 3.3.2 High Resolution Soft X-ray Beam Lines 3.3.3 High Resolution Hard X-ray Beam Lines 3.3.4 Laboratory Vacuum Ultraviolet Sources 3.3.5 Laser Sources 3.3.6 Miscellaneous Subjects 3.4 Electron Spectrometers 3.4.1 Hemispherical Analyzers 3.4.2 Cylindrical Mirror Analyzers 3.4.3 Two-Dimensional Analyzers 3.4.4 Time-of-Flight Analyzers 3.5 Sample Preparation and Characterization 3.5.1 Ion Sputtering, Scraping, Fracturing and Cleavage 3.5.2 In-Situ Sample Growth and Surface Analysis 3.5.3 Samples at Low Temperatures or at Ambient Pressure 3.6 Methodology 3.6.1 Angle-Integrated Photoelectron Spectroscopy 3.6.2 Resonance Photoemission and Constant Initial State Spectrum 3.6.3 Angle-Resolved Photoelectron Spectroscopy 3.6.4 Photoelectron Spectroscopy in the μm and nm Regions 3.6.5 Momentum Microscope References 4 Bulk and Surface Sensitivity of Photoelectron Spectroscopy 4.1 Concept of Inelastic Mean Free Path 4.2 How to Separate the Bulk and Surface Contributions in the Spectra References 5 Examples of Angle-Integrated Photoelectron Spectroscopy 5.1 Valence Band Spectra 5.2 Core Level Spectra 5.3 Multiplet Structures References 6 Angle Resolved Photoelectron Spectroscopy in the hν Region of 15 to 200 eV 6.1 General 6.2 Layered Materials 6.3 Rare Earth Compounds 6.4 One Dimensional Materials 6.5 Topological Insulators 6.6 Superconductors 6.7 Quantum Well States References 7 High-Resolution Soft X-ray Angle-Integrated and -Resolved Photoelectron Spectroscopy of Correlated Electron Systems 7.1 Angle-Integrated Soft X-ray Photoelectron Spectroscopy 7.1.1 Ce Compounds 7.1.2 Yb Compounds 7.1.3 Transition Metal Compounds 7.2 Angle-Resolved Soft X-ray Photoelectron Spectroscopy 7.2.1 Ce Compounds 7.2.2 La2−xSrxCuO4 and Nd2−xCexCuO4 7.2.3 Layered Ruthenates Sr2−xCaxRuO4 7.2.4 V6O13 and SrCuO2 7.2.5 Other Materials (VSe2, LaRu2P2, BiTeI) 7.3 Standing Wave References 8 Hard X-ray Photoelectron Spectroscopy 8.1 La1−xSrxMnO3, La2−xSrxCuO4 and Nd2–xCexCuO4 8.2 Sm Compounds 8.3 Pr Compounds 8.4 Yb Compounds 8.5 V Oxides 8.6 Recoil Effects 8.7 Angle-Resolved Hard X-ray Photoelectron Spectroscopy 8.8 Polarization Dependence of Hard X-ray Photoelectron Spectroscopy 8.9 Linear Dichroism in Angle-Resolved Core-Level Photoemission 8.9.1 Formulations and Simulations of Polarization-Dependent Angle-Resolved Core-Level Photoemission Spectra 8.9.2 Partially Filled 4f States Under Crystalline Electric Fields 8.9.3 Tetragonal and Cubic Yb Compounds 8.9.4 Tetragonal Sm Compounds 8.9.5 Cubic Pr Compounds 8.9.6 Tetragonal Ce Compounds References 9 Very Low Photon Energy Photoelectron Spectroscopy 9.1 Angle Integrated and Resolved ELEPES by Laser Excitation 9.1.1 Angle-Integrated Measurements 9.1.2 Angle-Resolved Measurements 9.2 ELEPES by Synchrotron Radiation 9.3 ELEPES by Microwave-Excited Rare Gas Lamp 9.4 Two-Photon Excitation Photoelectron Spectroscopy References 10 Magnetic Dichroism and Spin Polarization in Photoelectron Spectroscopy 10.1 Magnetic Circular and Linear Dichroism in Photoelectron Spectroscopy 10.2 Principle and Instrumentation for Spin Polarized Photoelectron Spectroscopy 10.3 Spin Polarized Photoelectron Spectroscopy for Non-magnetic Materials 10.3.1 Pt 10.3.2 High-Tc Cuprate 10.3.3 Rashba Effect and Topological Insulators 10.4 Spin Polarized Photoelectron Spectroscopy of Magnetic Materials References 11 Momentum Microscopy 11.1 The Concept of Momentum Space Imaging 11.1.1 Instrumental Aspects 11.1.2 Energy and Momentum Resolution 11.2 Evolution and Applications of Momentum Microscopy 11.2.1 Fermi Surface Mapping with a High-Pass Energy Filter 11.2.2 Aberration Compensated Energy Filter 11.2.3 Electronic Structure of Noble Metals 11.2.4 High-Resolution Spectroscopy of Layered Semiconductors 11.2.5 Double-Pass Energy Filter 11.2.6 Other Dispersive Energy Filters 11.3 Time-of-Flight Momentum Microscopy 11.3.1 Time-of-Flight Electron Energy Analysis 11.3.2 Energy Resolution of a Time-of-Flight Spectrometer 11.3.3 Rapid Band Structure Mapping 11.3.4 Time-Resolved Spectroscopy 11.4 High-Energy Momentum Microscopy 11.4.1 Hard X-ray Photoemission Microscopy and Spectroscopy 11.4.2 Bulk Fermi Surface Tomography 11.5 Spin-Resolved Momentum Microscopy 11.5.1 Working Principle of Imaging Spin Filters 11.5.2 Properties of the Spin-Filter Crystal 11.5.3 Measurements Principles 11.5.4 Spin-Resolved ToF Momentum Microscopy 11.5.5 Imaging Complex Spin Textures 11.5.6 Electronic Structure of Ferromagnets 11.5.7 Efficiency of Multichannel Spin Filters 11.6 Spin-Resolved Photoelectron Microscopy 11.7 Laser Excited Momentum Microscopy 11.7.1 Spin Texture of Topological Insulators 11.7.2 Surface Doping Effects References 12 Photoelectron Diffraction and Photoelectron Holography References 13 Inverse Photoemission 13.1 General Concept 13.2 Isochromat IPES 13.3 Angle-Resolved IPES 13.4 IPES with a Fixed Incident Electron Energy 13.5 IPES of Quantum Well States 13.6 Spin Polarized Inverse Photoemission Spectroscopy (SP-IPES) 13.6.1 Principle and Instrumentation 13.6.2 Several SP-IPES Studies References 14 Complementary Techniques for Studying Bulk Electronic States 14.1 Core Absorption Spectroscopy 14.2 Infrared and Far-Infrared Spectroscopy 14.3 Resonance Inelastic X-ray Scattering 14.4 Magneto Optical Studies: Core Absorption and Soft X-ray Resonance Inelastic Scattering References 15 Surface Spectroscopy by Scanning Tunneling Microscope 15.1 Scanning Tunneling Spectroscopy by Scanning Tunneling Microscope 15.2 Scanning Tunneling Spectroscopy and Momentum Microscopy of SmB6 References 16 Summary and Outlook 16.1 Bulk Sensitive Electronic Structure Investigation: HAXARPES 16.2 Advances of Photoelectron Analyzers for ARPES and Momentum Microscopy 16.3 Electronic Structure Investigation of Micro-Nano Regions 16.4 Investigation of Complex Spin Textures in k-Space 16.5 Miscellaneous 16.6 Outlook References List of Samples Index