Quantum computing requires a major paradigm shift in hardware design, and in figuring out how problems can be solved in these novel designs. Conventional computing depends on the use and implementation of unambiguous logical and system states in both hardware and software. Quantum computing, on the other hand, depends on the indeterminacy of quantum states to create an analog of parallel processing, for speedy and secure processing.
Research leading to the design of quantum computing devices is an active endeavor on the frontiers of computing. This book reports on the current status of the technologies, and the underlying quantum physics supporting the technologies. Each chapter has its own references to the archival literature. Most of the references appear to be from standard physics journals, which should be accessible in research libraries.
There is a large group of authors who wrote the chapters as team collaborations. The chapters are not revised papers from a conference, but original contributions. Although the discussions are extensive, they are not as thorough as those in a textbook. Readers will have to backtrack through the references to augment their study.
Readers may perceive some redundancy in the presentation of some theoretical material supporting the different technologies. This is a positive feature. This is a resource book, and not every chapter needs to be read by a person interested in specific technologies. The technological threads connecting all of the chapters are “How can a logical bit be implemented?” and “How can a logic gate be constructed?”
After a brief preface, the authors begin the book with two chapters on quantum informatics and quantum computational systems. On these two chapters, the remainder of the book rests. The subsequent chapters discuss technologies: cavity quantum electrodynamics, cold confined ions and atoms, quantum dots, linear optics, superconducting devices, and nuclear magnetic resonance (NMR) computing. Although NMR computing is in the last chapter, it is perhaps the most mature and extensively studied technology. Solid state NMR may have the potential for scalable devices. There are five appendices that elaborate on physical and mathematical points that would distract the reader from the flow of the text in the main chapters: Bell’s inequalities, Fock-Darwin states, exchange energy for quantum dots, and transformation and homomorphism of quantum states.
In the authors’ preface, they wrote, “This book is written at a level suitable for an audience who [has] had some prior exposure to quantum computing and some maturity in atomic physics.” I would go a bit further. Readers who expect to get the most from this book should have a solid introduction in quantum computing and a firm foundation in atomic physics. Nonetheless, for readers with the proper prerequisites, this book is a good summary and exposition of the contemporary status of quantum computing technologies.