Quantum

This book highlights the findings and achievements in the major research plan “Detection and Interaction of Single Quantum States” funded by the National Natural Science Foundation of China (NSFC). The 8-year plan started in 2011 and consisted of 107 projects conducted by Chinese universities and research institutes. The book covers the plan's research background, achievements, and follow-up prospects. The plan aimed to tackle one of the major challenges for researchers worldwide—to establish precise detection and control of single quantum states in time, space, energy, and momentum. The plan integrated precise detection means with the ultrahigh resolution of time, space, and energy, under extreme conditions such as ultrahigh vacuum, ultralow temperature, high magnetic field, and ultrahigh pressure, using interdisciplinary research methods in physics, chemistry, informatics, and materials science. The book focuses on the exploration of new phenomena, theories, and concepts of single quantum states, describes new techniques and methods of single quantum states, and presents the purification and construction of single-quantum-state systems. It is a concise and valuable source of information for researchers in quantum science and graduate students interested in the research field.

In this volume the fundamental theory of open quantum systems is revised in the light of modern developments in the field. A unified approach to the quantum evolution of open systems is presented by merging concepts and methods traditionally employed by different communities, such as quantum optics, condensed matter, chemical physics and mathematical physics.

Quantum theory presents a strange picture of the world, offering no real account of physical properties apart from observation. Neils Bohr felt that this reflected a core truth of nature: "There is no quantum world. There is only an abstract mathematical description." Among the most significant developments since Bohr’s day has been the theorem of John S. Bell. It is important to consider whether Bell’s analysis supports such a denial of microrealism. In this book, we evaluate the situation in terms of an early work of Erwin Schrödinger. Doing so, we see how Bell’s theorem is conceptually related to the Conway and Kochen Free Will theorem and also to all the major anti-realism efforts. It is easy to show that none of these analyses imply the impossibility of objective realism. We find that Schrödinger’s work leads to the derivation of a new series of theoretical proofs and potential experiments, each involving “entanglement,” the link between particles in some quantum systems.

Bohr and Planck helped shaped the cultural landscape of the world today. Now their work is available here in a digestible, pocket format for the modern reader.

In recent years, remarkable progress in the fabrication of novel mesoscopic devices has produced a revival of interest in quantum Hall physics. New types of measurements, more precise and efficient than ever, have made it possible to focus closely on the electronic properties of quantum Hall edge states. This is achieved by applying charge and heat currents at mesoscopic length scales, attaching metallic gates and Ohmic contacts, and splitting edge channels with the help of quantum point contacts. The experiments reveal fascinating new phenomena, such as the interference, statistics, and topological phase shifts of fractionally charged quasi-particles, strong interaction and correlation effects, and phase transitions induced by non-Gaussian fluctuations. The thesis discusses some puzzling results of these experiments and presents a coherent picture of mesoscopic effects in quantum Hall systems, which accounts for integer and fractional filling factors and ranges from microscopic theory to effective models, and covers both equilibrium and non-equilibrium phenomena.