Photonic Quantum Technologies: Science and Applications

Description

Photonic Quantum Technologies Brings together top-level research results to enable the development of practical quantum devices In Photonic Quantum Technologies: Science and Applications, the editor Mohamed Benyoucef and a team of distinguished scientists from different disciplines deliver an authoritative, one-stop overview of up-to-date research on various quantum systems. This unique book reviews the state-of-the-art research in photonic quantum technologies and bridges the fundamentals of the field with applications to provide readers from academia and industry, in one-location resource, with cutting-edge knowledge they need to have to understand and develop practical quantum systems for application in e.g., secure quantum communication, quantum metrology, and quantum computing. The book also addresses fundamental and engineering challenges en route to workable quantum devices and ways to circumvent or overcome them. Readers will also find: A thorough introduction to the fundamentals of quantum technologies, including discussions of the second quantum revolution (by Nobel Laureate Alain Aspect), solid-state quantum optics, and non-classical light and quantum entanglementComprehensive explorations of emerging quantum technologies and their practical applications, including quantum repeaters, satellite-based quantum communication, quantum networks, silicon quantum photonics, integrated quantum systems, and future visionPractical discussions of quantum technologies with artificial atoms, color centers, 2D materials, molecules, atoms, ions, and optical clocks Perfect for molecular and solid-state physicists, Photonic Quantum Technologies: Science and Applications will also benefit industrial and academic researchers in photonics and quantum optics, graduate students in the field; engineers, chemists, and computer and material scientists. Cover Volume1 Title Page Copyright Contents Preface Abstracts and Keywords Chapter 1 Introduction to Quantum Photonics 1.1 The Photon 1.2 The Light–Matter Interaction 1.3 Single‐Photon Sources 1.4 Single‐Photon Detectors 1.5 Applications of the Photon in Quantum Technology 1.5.1 Quantum Communication 1.5.2 Quantum Simulation 1.5.3 Quantum Computing References Part I Fundamentals of Quantum Technologies Chapter 2 The Second Quantum Revolution: From Basic Concepts to Quantum Technologies1 2.1 Two Quantum Revolutions 2.2 The First Quantum Revolution 2.2.1 The Electronics and Information Age: Quantum Mechanics Applied 2.3 Entanglement and Bell's Theorem 2.3.1 The Bohr–Einstein Debate 2.3.2 Bell's Theorem 2.4 Quantum Mechanics and Single Objects 2.4.1 From the Ensemble to the Single Quantum System 2.4.2 Quantum Jumps in Action: New Clocks and New Theoretical Methods 2.4.3 From Microscopic to Mesoscopic 2.4.4 From Mesoscopic to Macroscopic: Decoherence 2.5 The Second Quantum Revolution in Action: Quantum Information, Quantum Technologies 2.5.1 Quantum Cryptography 2.5.2 Quantum Computing 2.5.3 Quantum Computing with Real, Imperfect Systems 2.5.4 Other Quantum Technologies 2.6 Conclusion: Questioning Quantum Mechanics Is Fruitful References Chapter 3 Solid‐State Quantum Emitters 3.1 Introduction 3.2 Photon Correlation Functions 3.3 Quantum Emitters 3.4 Single‐Photon Sources 3.5 Purcell Enhancement 3.6 Photon Coherence 3.7 Deterministic Excitation of Quantum Emitters 3.8 Conclusions References Chapter 4 Single‐Photon Sources for Multi‐Photon Applications 4.1 Motivation and Applications 4.2 Nonlinear Optical Sources 4.2.1 Principles 4.2.1.1 Spontaneous Parametric Down‐Conversion 4.2.1.2 Spontaneous Four‐Wave Mixing 4.2.1.3 Phase Matching 4.2.2 Photon‐Number Purity and Heralding 4.2.3 Indistinguishability 4.2.4 Spectral Purity 4.2.4.1 Methods for High‐Purity Down‐Conversion Sources 4.2.5 Photon‐Number Purity and Brightness 4.2.6 Multiplexing Schemes 4.3 Quantum Dots 4.3.1 Advanced Excitation Schemes 4.3.2 Engineering the Quantum Dot Environment 4.3.3 Demultiplexing References Chapter 5 Quantum Key Distribution Protocols 5.1 Introduction 5.2 Fundamentals of QKD 5.2 BB84 Protocol 5.1 5.3 Security Framework 5.3.1 Security Definition 5.3.2 Security Proof Techniques 5.4 Practicalities 5.4.1 Decoy‐State QKD 5.4.2 Measurement‐Device‐Independent QKD 5.4.3 Other Practical QKD Protocols 5.4.4 The Problem of Implementation Security 5.5 Components of a QKD System 5.5.1 Light Sources 5.5.2 Single‐Photon Detectors 5.5.3 Linear Optical Elements 5.6 Performance 5.7 Conclusions and Future Challenges Acknowledgments References Chapter 6 From Basic Science to Technological Development: The Case for Two Avenues 6.1 Introduction 6.2 Thermodynamics for an Energetically Efficient Quantum Information Processing 6.2.1 On Step 2 6.2.2 On Step 4 6.3 Data Intensive Tools for Quantum Computing Science 6.4 Conclusions Acknowledgments References Chapter 7 Quantum Networks in Space 7.1 Global Communication 7.2 Challenges in Global Secure Quantum Networks 7.3 Untrusted Nodes 7.3.1 Mirror Systems and Coupled Systems 7.3.2 Sources 7.3.3 Repeater 7.4 Currently Available Technology 7.4.1 Required Technology 7.4.2 Technology Readiness Level (TRL) 7.4.3 Optical Link Technologies 7.4.4 Sources 7.4.5 Repeater 7.4.5.1 Overview 7.4.5.2 Optical Fibers 7.4.5.3 Memories 7.4.5.4 Sum of Its Parts 7.5 Summary 7.6 Acronyms References Part II Atoms, Ions, and Molecules: From Experimental Techniques to Recent Progress Chapter 8 Fluorescence Spectroscopy in Planar Dielectric and Metallic Systems 8.1 Introduction 8.2 Theory 8.2.1 Ideal Electric Dipole Emitter 8.2.2 Interaction of Plane Waves with Planar Layered Structures 8.2.3 Electric Dipole Emission 8.2.4 Angular Distribution of Radiation and Detection Efficiency 8.2.5 Excitation Intensity Distribution 8.2.6 Synthesis 8.3 Applications 8.3.1 Absolute Quantum Yield Measurements 8.3.2 MIET/GIET imaging 8.4 Conclusion References Chapter 9 Single Trapped Neutral Atoms in Optical Lattices 9.1 Introduction 9.2 Tools for Trapping Single Neutral Atoms 9.2.1 Trapping Neutral Atoms 9.2.1.1 Magnetic Traps 9.2.1.2 Optical Dipole Traps 9.2.2 Preparing and Observing Individual Neutral Atoms 9.2.2.1 Single Neutral Atoms in a MOT 9.2.2.2 Single Neutral Atoms in Optical Dipole Traps 9.2.2.3 Detecting Single Atoms in MOTs and ODTs with High Efficiency 9.2.2.4 Detecting Single Atoms Using Optical Cavities 9.2.2.5 Detecting the Qubit State of Trapped Atoms in Free Space 9.2.2.6 Detecting the Qubit State of Atoms Trapped in Cavities 9.2.2.7 Detecting the Position of Single Atoms with High Fidelity 9.2.2.8 Simultaneous Detection of Quantum State and Position 9.2.3 Precision Transport of Atoms 9.2.3.1 Optical Conveyor Belt 9.2.3.2 Spin‐Dependent Optical Lattice 9.2.3.3 Two Overlapped Optical Conveyor Belts with Orthogonal Polarizations 9.2.3.4 Optical Conveyor Belt for Two Dimensions 9.2.4 Controlling the Motional Atomic State 9.2.5 Addressing and Controlling the Atom Position 9.3 Quantum Control of Single Trapped Atoms 9.3.1 Quantum State Transport 9.3.2 Quantum Speed Limit of Atomic Motion 9.3.3 Quantum Delocalization 9.3.3.1 Spin‐Dependent Transport 9.3.3.2 Single‐Atom Interferometer 9.3.4 Quantum Walks of Single Atoms 9.3.5 Applications of Quantum Walks 9.3.5.1 Electric and Magnetic Quantum Walks 9.3.5.2 Test of the Leggett–Garg Inequality 9.3.6 Single Atoms as Sensors 9.3.6.1 Single Atoms as Localized Quantum Probes 9.3.6.2 Single Atoms for Environmental Applications 9.4 Short Conclusions Acknowledgments References Chapter 10 Long‐Distance Entanglement of Atomic Qubits 10.1 Qubit Encoding in 87Rb 10.2 Trapping Single Atoms 10.3 State Preparation, Control, and Measurement of Single Atoms 10.3.1 Creation of Atom–Photon Entanglement 10.3.2 Measurement of the Atomic State 10.4 Coherence of the Atomic States 10.4.1 Interaction with Magnetic and Optical Fields 10.4.2 Control of the Magnetic Fields 10.4.3 Decoherence Caused by Polarization Dependent AC‐Stark Shift and Motion of the Atom 10.5 Creation of Long‐Distance Atom–Atom Entanglement 10.5.1 Heralded Entanglement via Entanglement Swapping 10.5.2 Operation of the Two‐Trap Setup 10.5.3 Creation and Verification of the Atom–Atom Entanglement 10.6 Employing Distributed Entanglement 10.6.1 Bell Test Simultaneously Closing Detection and Locality Loopholes 10.6.2 Advanced Protocols Based on Distributed Entanglement 10.6.3 Toward Long‐Distance Quantum Networks Acknowledgments References Chapter 11 Collective Light Emission of Ion Crystals in Correlated Dicke States 11.1 Introduction 11.2 Structure of the Article 11.3 Fundamentals of Trapping and Laser Cooling of Ions in a Paul Trap 11.4 Light Emission of Uncorrelated Ion Crystals 11.5 Theory of Correlated Dicke States Among Trapped Ions via Projective Measurements of Scattered Photons 11.6 Theory of Collective Light Emission of Ion Crystals in Correlated Dicke States 11.7 Theory of Measuring Collective Light Emission from Linear Ion Crystals in Dicke‐Correlated States 11.8 Measurement of the Collective Light Emission of a Two Ion Crystal 11.9 Conclusion and Outlook Acknowledgments References Chapter 12 Single‐Molecule Magnets Spin Devices 12.1 Introduction 12.2 SMMs and Quantum Effects 12.2.1 Quantization 12.2.2 Quantum Coherence 12.2.3 Quantum Tunneling of the Magnetization 12.2.4 Quantum Bits and Multilevel Systems 12.3 SMMs for Single‐Molecule Devices 12.3.1 Spin Transistors 12.3.2 Spin Valve 12.4 SMMs for Quantum Technologies 12.4.1 Quantum Sensing 12.4.2 Quantum Simulations 12.4.3 Quantum Computing 12.4.4 Quantum Communication 12.5 Conclusions References Chapter 13 Molecular‐Ion Quantum Technologies 13.1 Introduction 13.2 Experimental Techniques 13.2.1 Ion Trapping 13.2.2 Generation of Molecular Ions and Their State Initialization 13.2.3 Cooling of Trapped Ions 13.3 Destructive State‐Readout Techniques 13.4 Quantum‐Logic Experiments on Single Trapped Molecular Ions 13.4.1 Quantum‐Nondemolition Molecular State Readout by State‐Dependent Coherent Motional Excitation 13.4.2 Molecular State Detection and Spectroscopy via a Motional Qubit 13.4.3 Molecular Quantum Logic Spectroscopy Using Resolved‐Sideband Raman Transitions 13.5 Outlook on Future Developments and Conclusions Acknowledgments References Chapter 14 Optical Atomic Clocks 14.1 Introduction 14.2 Optical Atomic Clocks 14.3 Optical Clocks with a Single Trapped 171Yb+ Ion 14.4 Outlook on Future Developments Acknowledgments References Volume 2 Title Page Copyright Contents Preface Abstracts and keywords Part III Spin Qubits and Quantum Memories: From Spin Properties to Physical Realizations Chapter 15 Coherent Spin Dynamics of Colloidal Nanocrystals 15.1 Introduction 15.2 Spin‐Level Structure of Neutral and Charged Excitons 15.3 Photoluminescence in Magnetic Field 15.4 Time‐Resolved Faraday Rotation 15.5 Dynamics of Photocharging Visualized via Electron Spin Coherence 15.6 Spin–Flip Raman Scattering 15.7 Surface Magnetism 15.8 Diluted Magnetic Semiconductor Colloidal NCs 15.9 New Materials: Perovskite QDs 15.10 Conclusions Acknowledgments References Chapter 16 Relaxation of Electron and Hole Spin Qubits in III–V Quantum Dots 16.1 Introduction 16.1.1 Solid‐State Spin Qubits 16.1.2 Spin‐Qubits for Measurement‐Based Quantum Information Processing (QIP) 16.1.3 Contents of the Chapter 16.2 Fundamental Properties and Devices Investigated 16.2.1 Key Physical Electronic and Optical Properties of Self‐Assembled Quantum Dots 16.2.2 Optical Spin Storage Photodiodes 16.2.3 Reset and Charge Readout 16.2.4 Optical Manipulation: Geometric Phase Control and Spin Echo 16.3 Relaxation Dynamics of Electron Spin Qubits 16.3.1 Theoretical Background: A Historical Perspective 16.3.2 Inhomogeneous Dephasing in a Fluctuating Overhauser Field 16.3.3 Decoherence as a Result of Time Dependent Changes in the Nuclear Spin Bath 16.3.4 Complete Depolarization Due to Dipolar Interactions in the Nuclear Spin Bath 16.4 Electron Spin Relaxation Studied in Experiments 16.4.1 Monitoring the Electron Spin Qubit Relaxation 16.5 Hole Spin Relaxation in Single Quantum Dots 16.5.1 Theory of the Anisotropic Hyperfine Coupling of Holes 16.5.2 Nuclear Spin Dynamics 16.5.3 Hole Spin Storage Devices 16.5.4 Fast Dynamics of the Central Spin 16.5.5 Slow Part of the Relaxation 16.6 Summary Ackowledgments References Chapter 17 Ensemble‐Based Quantum Memory: Principle, Advance, and Application 17.1 Introduction 17.2 Memory Schemes 17.2.1 Optical Delay Line 17.2.2 Electromagnetically Induced Transparency 17.2.3 Atomic Frequency Comb 17.2.4 DLCZ Scheme 17.2.5 Other Schemes 17.3 Performance Criteria 17.3.1 Working Wavelength 17.3.2 Efficiency 17.3.3 Storage Time 17.3.4 Fidelity 17.3.5 Bandwidth 17.3.6 Multimode Capacity 17.3.7 Integratability 17.4 Physical Realization 17.4.1 Gas Atomic Ensemble 17.4.2 Solid‐State Atomic Ensemble 17.5 Applications 17.5.1 Linear‐Optical Quantum Computing 17.5.2 Quantum Repeater 17.5.3 Quantum Key Distribution 17.5.4 Detection of Single Photons 17.6 Summary and Outlook References Part IV Solid‐State and van der Waals Material Platforms: From Single Quantum Emitters to Hybrid Integration Chapter 18 Telecom Wavelengths InP‐Based Quantum Dots for Quantum Communication 18.1 Introduction 18.2 Basic Concepts 18.2.1 Artificial and Real Atoms 18.2.2 Formation of Quantum Dots 18.2.3 Excitons in Quantum Dots 18.3 Low‐Density InP‐Based Quantum Dots 18.3.1 Low‐Density InAs QDs on Distributed Bragg Reflectors 18.3.2 Quantum Dots in Quaternary Barriers: Round‐Shaped Dots 18.3.2.1 Epitaxial Quantum Dot Growth 18.3.2.2 Structural Properties of Quantum Dots 18.3.2.3 Charged Quantum Dots 18.3.3 Quantum Dots in Binary Barriers: Symmetric Dots 18.3.3.1 Optical Properties 18.3.3.2 Magneto‐Optical Studies 18.3.3.3 Photon Extraction Efficiency 18.3.3.4 Quantum Dots in Photonic Crystal Cavities 18.3.3.5 Radiative Lifetime 18.4 Symmetric InP‐Based Quantum Dots as Quantum Light Sources 18.5 Challenges and Future Directions Acknowledgments References Chapter 19 Quantum Optics with Solid‐State Color Centers 19.1 Introduction 19.2 Color Centers 19.2.1 Diamond 19.2.1.1 Material Considerations 19.2.1.2 Nitrogen‐Vacancy Defect Center 19.2.1.3 Group IV Defect Centers 19.2.1.4 Other Color Centers in Diamond 19.2.2 Silicon Carbide 19.2.2.1 Material Properties 19.2.2.2 Prominent Color Centers 19.2.3 Other Host Materials 19.2.4 Optical Micro‐ and Nanostructures for Controlled Light‐Matter Interaction 19.2.4.1 Fabrication and Nanostructures in Diamond 19.2.4.2 Fabrication and Nanostructures in SiC 19.3 Applications 19.3.1 Color Centers as Quantum Emitters 19.3.1.1 Quantum Emitters at Room Temperature 19.3.1.2 Quantum Emitters at Cryogenic Temperatures 19.3.1.3 State‐of‐the‐art 19.3.2 Color Centers as Quantum Memories 19.3.2.1 Considerations and Figures of Merit 19.3.2.2 Physical Considerations on Cycling Transitions: Spin Initialization and State Read‐out of Qubits in Diamond 19.3.2.3 State‐of‐the‐Art 19.3.3 Color Centers for 2‐Qubit Quantum Gates 19.3.3.1 Color Centers for Spin–Photon Entanglement 19.3.3.2 Color Centers in Solid‐State Multi‐Qubit Registers 19.3.3.3 Color Centers for Remote Spin–Spin Entanglement 19.4 Proposals and Perspectives 19.4.1 Applications 19.4.2 Directions and Remaining Challenges References Chapter 20 Quantum Photonics with 2D Semiconductors 20.1 Introduction 20.1.1 Hexagonal Boron Nitride 20.1.2 Transition Metal Dichalcogenide Semiconductors 20.1.3 Van der Waals Heterostructures 20.2 Semiconductor Quantum Emitters 20.3 Engineering 2D Semiconductor Quantum Emitters 20.3.1 Dielectric and Electrostatic Engineering 20.3.2 Strain‐Tuning 20.3.3 Site‐Controlled Implantation 20.3.4 Moiré Heterostructures 20.3.5 Heterostructure Device Functionalization 20.3.6 Integrated Photonics with 2D Quantum Emitters 20.4 Outlook Acknowledgments References Chapter 21 Nano‐Opto‐Electro‐Mechanical Systems for Integrated Quantum Photonics 21.1 Introduction and Overview 21.2 Device Principles 21.2.1 Tunable Beam Splitters 21.2.2 Device Speed 21.2.3 Electro‐mechanical Actuation 21.3 NOEMS Fabrication 21.4 Application of NOEMS to Quantum Photonics 21.4.1 Routing and Switching Single Photons 21.4.2 Controlling Light–Matter Interaction 21.5 Challenges and Perspectives References Chapter 22 Silicon Quantum Photonics ‐ Platform and Applications 22.1 Introduction 22.1.1 Fabrication Process 22.1.2 Passive Components 22.1.3 Active Components 22.2 Quantum State of Light on Silicon Photonics Platform 22.2.1 Toward Deterministic and Efficient Quantum Light Sources on Silicon Platform 22.2.2 Nonlinear Sources on Silicon 22.2.2.1 Fundamentals of Nonlinear Photon Sources 22.2.2.2 Multiplexing for Deterministic Photon Generation 22.2.2.3 Parasitic Effects 22.3 Applications 22.3.1 Quantum Information Processing 22.3.1.1 Measurement‐Based Model of Quantum Computation 22.3.1.2 Rudimentary Quantum Computers 22.3.2 Quantum Communications 22.3.2.1 Quantum Key Distribution 22.3.2.2 Future Quantum Networks 22.4 Outlook References Part V Emerging Quantum Technologies: Challenges and Potential Applications Chapter 23 Photonic Realization of Qudit Quantum Computing 23.1 Introduction to Qudit Quantum Computing 23.1.1 Universality and Examples of Qudit Gates 23.1.2 Examples of Qudit Quantum Algorithms 23.2 Qudit Implementation on Photonic Systems 23.2.1 Qudits in Time and Frequency Degrees of Freedom 23.2.2 Superconducting Bosonic Processor 23.3 Summary and Future Outlooks Acknowledgments References Chapter 24 Fiber‐Based Quantum Repeaters 24.1 Quantum Repeater Toolbox 24.1.1 Entanglement Distribution 24.1.2 Quantum Memories 24.1.3 Bell‐State Measurement 24.1.4 Entanglement Distillation 24.1.5 Quantum Error Correction 24.2 Quantum Repeaters Based on Heralded Entanglement Distribution 24.2.1 Probabilistic Quantum Repeaters 24.2.2 Semi‐Probabilistic Quantum Repeaters 24.2.3 Encoded Quantum Repeaters 24.3 Memory‐Less Quantum Repeaters 24.3.1 All‐photonic Quantum Repeaters 24.3.2 One‐way Quantum Repeaters 24.4 Summary and Discussion References Chapter 25 Long‐Distance Satellite‐Based Quantum Communication 25.1 Introduction 25.2 Ground‐Based Feasibility Studies 25.3 Satellite‐Based Quantum Communication Experiments with Micius 25.3.1 Satellite‐to‐Ground Quantum Key Distribution 25.3.2 Satellite‐Based Quantum Entanglement Distribution 25.3.3 Ground‐to‐Satellite Quantum Teleportation 25.4 Other Quantum Satellite Projects 25.5 Outlook References Chapter 26 Quantum Communication Networks for 6G 26.1 Introduction 26.2 What Is 6G? 26.3 6G Intrinsic Limitations: Why Do We Need Other Technologies? 26.4 The Vision of the Quantum Internet 26.5 The Architectural Convergence of Quantum Technologies and 6G References Index EULA