Polariton Physics: From Dynamic Bose–Einstein Condensates in Strongly-coupled Light–matter Systems to Polariton Lasers

Description

This book offers an overview of polariton Bose–Einstein condensation and the emerging field of polaritonics, providing insights into the necessary theoretical basics, technological aspects and experimental studies in this fascinating field of science. Following a summary of theoretical considerations, it guides readers through the rich physics of polariton systems, shedding light on the concept of the polariton laser, polariton microcavities, and the technical realization of optoelectronic devices with polaritonic emissions, before discussing the role of external fields used for the manipulation and control of exciton–polaritons. A glossary provides simplified summaries of the most frequently discussed topics, allowing readers to quickly familiarize themselves with the content. The book pursues an uncomplicated and intuitive approach to the topics covered, while also providing a brief outlook on current and future work. Its straightforward content will make it accessible to a broad readership, ranging from research fellows, lecturers and students to interested science and engineering professionals in the interdisciplinary domains of nanotechnology, photonics, materials sciences and quantum physics. Foreword Preface Acknowledgements Contents Acronyms Abbreviations Symbols 1 Towards Polariton Condensates and Devices 1.1 Introduction 1.2 Bose–Einstein Condensation of Polaritons 1.3 Endeavours to Achieve Polariton Lasers 1.4 More Exciton–Polariton Physics 1.5 Further Polaritons Not Detailed in This Book References 2 Fundamentals of Polariton Physics 2.1 The Origin of Polaritons 2.1.1 Fundamental Light–Matter Interaction 2.1.2 Cavity–Polaritons 2.2 Building-Blocks for Polariton Formation 2.2.1 Excitons in Quantum Wells 2.2.2 Confined Photons 2.3 Light–Matter Coupling 2.3.1 Exciton–Polaritons 2.3.2 Detuning Dependencies of Polariton Modes References 3 On the Condensation of Polaritons 3.1 Bosonic Many-Particle Features 3.1.1 Condensation of a Bose Gase 3.1.2 Criteria for Condensation 3.1.3 Dynamical Bose–Einstein Condensation of Polaritons 3.2 Excitation and Relaxation Dynamics 3.2.1 Excitation of Polaritons 3.2.2 Relaxation Towards the Energy Minimum 3.2.3 The Bottleneck Effect 3.2.4 Stimulated Ground-State Scattering References 4 The Concept of Polariton Lasing 4.1 Polariton Lasers—Electrically-Driven, Please! 4.1.1 What Is It About? 4.1.2 The Stimulated Scattering Process 4.2 Comparison with Photon Lasing (Lasing in the Weak-Coupling Regime) 4.2.1 What Is a Laser? 4.2.2 Stimulated Emission, Laser Conditions and Coherence Properties 4.2.3 Bernard–Duraffourg Condition in Semiconductors 4.2.4 Similarities and Differences Between Polariton and Photon Lasers 4.3 Identification of Polariton Lasing 4.3.1 Prerequisites and the Signatures of a Polariton Condensate 4.3.2 Overview on the Typical Experimental Procedure References 5 Optical Microcavities for Polariton Studies 5.1 Fabry–Pérot Microcavities 5.1.1 Distributed Bragg Reflectors 5.1.2 Planar Microresonator Structures 5.2 Implementation of Quantum Wells 5.2.1 Distribution of Quantum Wells 5.2.2 Number of Quantum Wells 5.2.3 Excitation Schemes 5.3 Optical Properties of Resonators 5.3.1 Free Spectral Range, Cavity Finesse, Photonic Density of States 5.3.2 Resonator Quality References 6 Technological Realization of Polariton Systems 6.1 Growth and Processing of Microcavity Devices 6.1.1 Epitaxy of Multilayered Structures 6.1.2 Potential Landscapes and Polariton Boxes 6.1.3 Doped Microresonators 6.1.4 Polariton Diodes 6.2 Microcavities for Different Material Systems 6.2.1 II/VI Microresonators 6.2.2 Inorganic Room-Temperature Polariton Systems 6.2.3 Organic Materials 6.2.4 Perovskite-Based Exciton–Polariton Systems 6.2.5 Monolayer Transition-Metal Dichalcogenides References 7 Spectroscopy Techniques for Polariton Research 7.1 Optical Spectroscopy 7.1.1 Reflection and Transmission Measurements 7.1.2 Micro-Photoluminescence Experiments 7.1.3 Micro-Electroluminescence Studies 7.2 Imaging and Real-Space Spectroscopy 7.2.1 Sample Imaging for Position Monitoring or Interferometry 7.2.2 Spatially-Resolved Spectra 7.3 Fourier-Space-Resolved Spectroscopy 7.3.1 Goniometer-Like Technique 7.3.2 Pinhole Translation Method 7.3.3 Single-Shot Angle-Resolved Acquisition 7.4 Time-Resolved Spectroscopy 7.4.1 Streak-Camera Measurements 7.4.2 Pump–Probe Techniques References 8 Optically-Excited Polariton Condensates 8.1 The Observation of Polariton Condensation 8.1.1 Condensate Studies in the Literature 8.1.2 Optical Pumping Schemes 8.1.3 Spectral Features of Polaritons 8.2 Condensation Experimentally Characterized 8.2.1 Real-Space and Momentum-Space Distribution of Condensate Emission 8.2.2 Stimulated Scattering and Macroscopic Ground-State Occupation 8.2.3 Link to BEC via Spatial Coherence Measurements 8.2.4 Photon Statistics 8.3 Special Condensate Features 8.3.1 Polaritons at Their Extremes 8.3.2 Coherent Polariton Lasers 8.3.3 Superfluidity and Vortices in Condensates References 9 Polaritons in External Fields 9.1 Effects of External Fields on Quantum-Well Excitons 9.1.1 Electro-Optical Tuning 9.1.2 Coupling to Strong Transient Electric Fields 9.1.3 Magneto-Optics with Excitons 9.2 Magneto-Polaritons in Microcavity Systems 9.2.1 Manipulating the Excitonic Component of Polaritons 9.2.2 Spinor Condensates in External Magnetic Fields 9.3 Interaction with Transient Fields 9.3.1 Terahertz Radiation and Polaritons 9.3.2 Addressing the Dark Side of Polaritons References Appendix Glossary Index