Charge and Spin Transport in Disordered Graphene-Based Materials (eBook)

Dinh Van Tuan studied theoretical Physics at Ho Chi Minh City University of Science and obtained a masters degree in Theoretical and Mathematical Physics. He then pursued his Ph.D. work at ICN2 from September 2011 till September 2014 during which he developed the first spin dynamics theoretical studies on weakly disordered graphene. Since then, he has been working as post doctorate researcher within the Graphene Flagship project (graphene-flagship.eu/), in the group of ICREA Prof. Stephan Roche. Dinh Van Tuan is in charge of the development of new methodologies to scrutinize the physics of the spin Hall effect in graphene based materials.

Supervisor's Foreword 7
Abstract 10
Acknowledgments 11
Contents 12
1 Introduction 14
References 16
2 Electronic and Transport Properties of Graphene 18
2.1 Introduction 18
2.2 Graphene and Dirac Fermions 19
2.2.1 Graphene 19
2.2.2 Low-Energy Dispersion 22
2.3 Electronic and Transport Properties of Disordered Graphene 25
2.4 Spin Transport in Graphene 33
2.4.1 Spin-Orbit Coupling in Graphene 33
2.4.2 Spin Transport in Graphene 40
References 45
3 The Real Space Order O(N) Transport Formalism 48
3.1 Electrical Transport Formalism 48
3.1.1 Electrical Resistivity and Conductivity 48
3.1.2 Semiclassical Approach 49
3.1.3 The Kubo-Greenwood Formula 53
3.1.4 Three Transport Regimes 57
3.1.5 The Kubo Formalism in Real Space 60
3.2 Spin Transport Formalism 62
3.2.1 Wavefunction and Random Phase State with Spin 63
3.2.2 Spin Polarization 64
3.2.3 Technical Details 66
References 67
4 Transport in Disordered Graphene 68
4.1 Transport Properties of Graphene with Vacancies 68
4.1.1 Introduction 68
4.1.2 Zero-Energy Modes and Transport Properties 70
4.2 Charge Transport in Poly-G 78
4.2.1 Introduction 78
4.2.2 Structure and Morphology of GGBs 79
4.2.3 Methods of Observing GGBs 82
4.2.4 Transport Properties of Intrinsic Poly-G by Simulation 86
4.2.5 Measurement of Electrical Transport Across GGBs 93
4.2.6 Manipulation of GGBs with Functional Groups 100
4.2.7 Challenges and Opportunities 106
4.3 Impact of Graphene Polycrystallinity on the Performance of Graphene Field-Effect Transistors 107
4.3.1 Introduction 107
4.3.2 Poly-G Effect on the Gate Electrostatics and I-V Characteristics of GFETs 108
4.4 Transport Properties of Amorphous Graphene 114
4.4.1 Introduction 114
4.4.2 Models of Amorphous Graphene 115
4.4.3 Electronic Properties 117
References 121
5 Spin Transport in Disordered Graphene 127
5.1 Spin Transport in Graphene: Pseudospin Driven Spin Relaxation Mechanism 127
5.1.1 Introduction 127
5.1.2 Spin Relaxation in Gold-Decorated Graphene 129
5.1.3 Further Discussion 136
5.2 Quantum Spin Hall Effect 142
5.2.1 Introduction 142
5.2.2 Adatom Clustering Effect on QSHE 143
References 149
6 Conclusions 152
Appendix A Time Evolution of theWave Packet 154
Appendix B Lanczos Method 157
Curriculum Vitae 160