This book highlights the novel research in quantum memory networking, especially quantum memories based on cold atomic ensembles. After discussing the frontiers of quantum networking research and building a DLCZ-type quantum memory with cold atomic ensemble, the author develops the ring cavity enhanced quantum memory and demonstrates a filter-free quantum memory, which significantly improves the photon-atom entanglement. The author then realizes for the first time the GHZ-type entanglement of three separate quantum memories, a building block of 2D quantum repeaters and quantum networks. The author also combines quantum memories and time-resolved measurements, and reports the first multiple interference of three single photons with different colors. The book is of good reference value for graduate students, researchers, and technical personnel in quantum information sciences.

This book highlights novel research work done on cold atom-based quantum networks. Given that one of the main challenges in building the quantum network is the limited entanglement distribution distance, this book presents some state-of-the-art experiments in tackling this challenge and, for the first time, establishes entanglement between quantum memories via metropolitan-scale fiber transmission. This achievement is accomplished by cooperating high-efficiency cold quantum memories, low-loss quantum frequency conversion modules, and long-fiber phase-locking techniques. In the book, the scheme design, experimental setup, data analyses, and numerous technical details are given. Therefore, it suits a broad readership that includes all students, researchers, and technicians who work in quantum information sciences.

This thesis presents an experimental study of quantum memory based on cold atomic ensembles and discusses photonic entanglement. It mainly focuses on experimental research on storing orbital angular momentum, and introduces readers to methods for storing a single photon carried by an image or an entanglement of spatial modes. The thesis also discusses the storage of photonic entanglement using the Raman scheme as a step toward implementing high-bandwidth quantum memory. The storage of photonic entanglement is central to achieving long-distance quantum communication based on quantum repeaters and scalable linear optical quantum computation. Addressing this key issue, the findings presented in the thesis are very promising with regard to future high-speed and high-capacity quantum communications.

This book constitutes the proceedings of the First International Conference on Quantum Communication and Quantum Networking, QuantumCom 2009, held in Naples, Italy, in October 2009. The 38 full papers were selected from numerous submissions. This conference has been devoted to the discussion of new challenges in quantum communication and quantum networking that extends from the nanoscale devices to global satellite communication networks. It placed particular emphasis on basic quantum science effects and on emerging technological solutions leading to practical applications in the communication industry, culminating with a special section on Hybrid Information Processing.

This important proceedings volume highlights the major scientific achievement of the last decade in atomic physics, namely the creation of the gaseous Bose-Einstein condensate, which was featured prominently at the XVIII International Conference on Atomic Physics (ICAP2002). Two recipients of the 2001 Nobel Prize delivered lectures at the meeting. Among the topics discussed were novel processes leading to degenerate Fermi gases in atom traps, creation of cold molecules, condensates in optical lattices, atoms in intense fields, tests of fundamental symmetries, quantum control and information, time and frequency standards.

In this age of the photon, information optics and photonics represent the key technologies to sustain our knowledge-based society. New concepts in classical and quantum-entangled light, coherent interaction with matter, and novel materials and processes have led to remarkable advances in today's information science and technology. The ICO is closely involved with information optics, as exemplified by the ICO topical meeting on Optoinformatics / Information Photonics (St. Petersburg, Russia, 2006), the ICO/ICTP Winter College on Quantum and Classical Aspects of Information Optics (Trieste, Italy, 2006), and the many ICO Prizes recently awarded on outstanding contributions on these topics. This book is in part based on these ICO activities.

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 entanglement Comprehensive 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 vision Practical 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.

The goal of the 8th International Symposium on Foundations of Quantum Mechanics in the Light of New Technology was to link recent advances in technology with fundamental problems and issues in quantum mechanics with an emphasis on quantum coherence, decoherence, and geometrical phase.The papers collected in this volume cover a wide range of quantum physics, including quantum information and entanglement, quantum computing, quantum-dot systems, the anomalous Hall effect and the spin-Hall effect, spin related phenomena, superconductivity in nano-systems, precise measurements, and fundamental problems. The volume serves both as an excellent reference for experts and a useful introduction for newcomers to the field of quantum coherence and decoherence.

This century has seen the development of technologies for manipulating and controlling matter and light at the level of individual photons and atoms, a realm in which physics is fully quantum-mechanical. The dominant experimental technology is the laser, and the theoretical paradigm is quantum optics. The Quantum World of Ultra-Cold Atoms and Light is a trilogy, which presents the quantum optics way of thinking and its applications to quantum devices. This book — The Physics of Quantum-Optical Devices — provides a comprehensive treatment of theoretical quantum optics. It covers applications to the optical manipulation of the quantum states of atoms, laser cooling, continuous measurement, quantum computers and quantum processors, superconducting systems and quantum networks. The subject is consistently formulated in terms of quantum stochastic techniques, and a systematic and thorough development of these techniques is a central part of the book. There is also a compact overview of the ideas of quantum information theory. The main aim of the book is to present the theoretical techniques necessary for the understanding of quantum optical devices, with special attention to those devices used in quantum information processing and quantum simulation. Although these techniques were developed originally for the optical regime, they are also applicable to electromagnetic radiation from the microwave realm to the ultra-violet, and for atomic systems, Josephson junction systems, quantum dots and nano-mechanical systems. For more information, please visit: http://europe.worldscientific.com/quantum-world-of-ultra-cold-atoms-and-light.html

This thesis offers a comprehensive introduction to surface acoustic waves in the quantum regime. It addresses two of the most significant technological challenges in developing a scalable quantum information processor based on spins in quantum dots: (i) decoherence of the electronic spin qubit due to the surrounding nuclear spin bath, and (ii) long-range spin-spin coupling between remote qubits. Electron spins confined in quantum dots (QDs) are among the leading contenders for implementing quantum information processing. To this end, the author pursues novel strategies that turn the unavoidable coupling to the solid-state environment (in particular, nuclear spins and phonons) into a valuable asset rather than a liability.