Measuring, Interpreting and Translating Electron Quasiparticle - Phonon Interactions on the Surfaces of the Topological Insulators Bismuth Selenide and Bismuth Telluride (eBook)

Dr Colin Howard was awarded a PhD from Boston University in 2015.  In 2012 he received the Gertrude and Maurice Goldhaber Award for Excellence in Physics Research, awarded annually to a single graduate student at Boston University for making exceptional contributions to research in their first year of graduate study.

Supervisor's Foreword 7
Abstract 9
Acknowledgments 11
Contents 13
List of Abbreviations 15
1 Introduction 16
References 20
2 Properties of Bi2Se3 and Bi2Te3 22
2.1 Crystal Structure 22
2.2 Bulk Vibrational Structure 24
2.3 Electronic Structure 26
References 29
3 Helium Atom-Surface Scattering (HASS) 30
3.1 The Benefits of HASS 30
3.2 The Surface Interaction Potential 31
3.3 The Kinematics of HASS 33
3.3.1 Elastic Scattering 33
3.3.2 Inelastic Scattering and Time-of-Flight Technique 34
References 37
4 Experimental Apparatus and Technique 38
4.1 Surface Laboratory Facilities 38
4.2 Source Chamber 38
4.3 Target Chamber 41
4.3.1 Production and Monitoring of UHV 42
4.3.2 Sample Manipulator 42
4.3.3 Sample Cleaver 43
4.3.4 Helium Detector 44
4.3.4.1 Continuous (Elastic) Detection 44
4.3.4.2 Time-of-Flight (Inelastic) Detection 44
References 46
5 Pseudocharge Phonon Model 47
5.1 Fundamentals of the Model 47
5.2 Adiatbatic Approximation, Ionic Self-Terms, and PC Self-Terms 48
5.3 Bulk Parameters 50
5.4 Surface Parameters 55
References 56
6 HASS Results from the Surface of Bi2Se3 and Bi2Te3 57
6.1 Elastic and Inelastic Scattering Results 57
6.2 Calculation of EPC Parameter in the RandomPhase Approximation 62
References 67
7 Translating Between Electron and Phonon Perspectives 68
7.1 Motivation 68
7.2 DFQ Self-Energy Formalism 69
7.3 Computational Results 71
7.4 Additional Supporting Results 75
References 77
8 Conclusion and Future Directions 78
8.1 Summary 78
8.2 Future Work 79
References 83
A Supplemental Material for Electron Self-Energy Analysis 84
A.1 Electron Green's Function 84
A.2 Bosonic Sums 90
B Numerical Evaluation of the DFQ Self-Energy 93
B.1 Hole Term 94
B.1.1 Above Dirac Point 94
B.1.2 Below Dirac Point 98
B.2 Particle Term 98
B.2.1 Above Dirac Point 98
B.2.2 Below Dirac Point 99
B.3 Interband Transitions 100