The physics of quantum information : proceedings of the 28th Solvay Conference on Physics : Brussels, Belgium, 19-21 May 2022

"Ever since 1911, the Solvay Conferences have shaped modern physics. The format is quite different from other conferences as the emphasis is placed on discussion. The 28th edition held in May 2022 in Brussels and chaired by David Gross and Peter Zoller continued this tradition and addressed some of the most pressing open questions in the fields of quantum information, gathering many of the leading figures working on a wide variety of profound problems. The proceedings contain the "rapporteur talks" giving a broad overview with unique insights by distinguished renowned scientists. These lectures cover the five sessions: The Physics of Quantum Information, Many-Body Entanglement, Quantum Information and Spacetime, Quantum Platforms, Quantum Algorithms. In the Solvay tradition, the proceedings also include the prepared comments to the rapporteur talks. The discussions among the participants - expert, yet lively and sometimes contentious - have been edited to retain their flavor and are reproduced in full. The reader is taken on a breathtaking ride through a fascinating field which is expanding rapidly"-- Provided by publisher CONTENTS The International Solvay Institutes 28th Solvay Conference on Physics Session 1: Opening / Overview Welcoming address by Marc Henneaux, director of the Solvay Institutes Welcoming address by David Gross, chair of the conference Welcoming address by Peter Zoller, chair of the conference Overview talk by John Preskill: The Physics of Quantum Information Abstract 1. Introduction 2. Background Modeling computation Quantifying information Quantum information Quantum computation What is a quantum computer? Quantum hardware Quantum error correction Quantum matter Quantum gravity Connections 3. Status and prospects Where are we now? Progress toward quantum error correction Fault-tolerance with the surface code Much better gate error rates? Creating quantum states of matter Opportunities in quantum simulation Challenges in quantum gravity Quantum gravity: can experiments help? 4. Some things I haven't mentioned 5. Conclusions References Discussion Introductory talk by David J. Wineland: Trapped ions meet quantum information processing, one perspective Abstract 1. Introduction and Background 2. Trapped ions meet quantum information 3. Simulation 4. Looking forward References Introductory talk by Peter W. Shor: The Early Days of Quantum Computation Abstract References Session 2: Many-Body Entanglement Rapporteur talk by Frank Verstraete: Quantum information and many-body systems Abstract 1. Introduction 2. Topological order and quantum error correction 2.1. Topological Order = Error Correction 2.2. Topological order and quantum information 3. The entanglement structure of equilibrium many-body systems 3.1. Using quantum computers to nd ground states 3.2. The illusion of Hilbert space, area laws, and entanglement Hamiltonians 3.3. Tensor networks 3.3.1. Entanglement patterns 3.3.2. TDVP and tangent spaces 3.3.3. Symmetries 3.3.4. Measurement-based quantum computation 4. Entanglement in non-equilibrium systems 4.1. Lieb-Robinson bounds 4.2. Thermalization 4.3. Floquet phases 4.4. Measurement-induced phase transitions in quantum circuits 5. Challenges References Discussion Rapporteur talk by Misha Lukin: Programmable quantum machines for probing entanglement in many-body systems Abstract 1. Programmable Quantum Simulators 2. Quantum simulations of entangled matter 3. Quantum matter away from equilibrium, entanglement and scrambling 4. Testing quantum algorithms 5. Outlook: new architectures and scaling up Acknowledgments References Discussion Prepared comments Discussion Prepared comments Discussion Session 3: Quantum Information and Spacetime Rapporteur talk by Douglas Stanford: Quantum information and spacetime Abstract 1. The "central dogma" of black hole physics 2. Examples with simple correlators 2.1. Example 1: thermalization of perturbations 2.2. Example 2: chaos 3. Three slogans connecting spacetime to QI 3.1. Slogan 1: the bulk is the geometrization of entanglement 3.2. Slogan 2: the bulk is an error-correcting code 3.3. Slogan 3: the bulk is a tensor network 4. A puzzle Acknowledgments References Discussion Prepared comments Discussion Prepared comments Discussion Rapporteur talk by Netta Engelhardt: The Entropy of Hawking Radiation Abstract 1. Introduction 2. Hawking radiation and information loss 3. Computing the Page curve for Hawking radiation 4. Decoding the black hole interior 5. Concluding remarks References Prepared comment Discussion Session 4: Quantum Platforms Rapporteur talk by Rainer Blatt: The Trapped-Ion Platform for Quantum Information Processing Abstract 1. Introduction 2. Qubits, interactions, quantum gate operations with trapped ions 3. Quantum information toolbox with trapped ions 4. Quantum computation and quantum simulation 4.1. Quantum computation 4.2. Quantum simulation 5. Scaling the ion trap quantum computer 6. Logical qubits and fault-tolerance with trapped ions 7. Conclusion Acknowledgments References Rapporteur talk by Robert J. Schoelkopf: Superconducting Circuits as a Platform for Quantum Computation Abstract 1. Introduction 2. Basics of superconducting qubits 3. Circuit QED 4. Current state of play 5. The challenge of error correction 5.1. Multiqubit codes 5.2. Bosonic codes 5.3. Some considerations for error correction 6. Computing architectures and scaling technologies 6.1. Considerations for architectures and scaling 7. Future prospects and outlook References Prepared comment Discussion Prepared comments Discussion Session 5: Quantum Algorithms Rapporteur talk by Scott Aaronson: How Much Structure Is Needed for Huge Quantum Speedups? Abstract 1. Introduction 2. The circuit model and the black-box model 3. A tour of exponential quantum speedups 4. The Yamakawa-Zhandry breakthrough 5. Near-term exponential speedups: Sampling-based quantum supremacy 6. Quantum speedups in the black-box model 7. The need for structure in quantum speedups: Lessons from the black-box model 8. Future directions and conclusions Acknowledgments References Discussion Prepared comments Discussion Prepared comment Rapporteur talk by Daniel Gottesman: Opportunities and Challenges in Fault-Tolerant Quantum Computation Abstract 1. Introduction 2. Current state of the art 3. Low-density parity check codes 4. Hardware-speci c fault tolerance 5. Fault tolerance as a space-time code 6. A framework for describing spacetime codes 7. Conclusion Acknowledgments References Discussion Prepared comments Discussion Closing Session