In the 1990's it was realized that quantum physics has some spectacular applications in computer science. This book is a concise introduction to quantum computation, developing the basic elements of this new branch of computational theory without assuming any background in physics. It begins with an introduction to the quantum theory from a computer-science perspective. It illustrates the quantum-computational approach with several elementary examples of quantum speed-up, before moving to the major applications: Shor's factoring algorithm, Grover's search algorithm, and quantum error correction. The book is intended primarily for computer scientists who know nothing about quantum theory, but will also be of interest to physicists who want to learn the theory of quantum computation, and philosophers of science interested in quantum foundational issues. It evolved during six years of teaching the subject to undergraduates and graduate students in computer science, mathematics, engineering, and physics, at Cornell University.

### Contents

Preface; 1. Cbits and Qbits; 2. General features and some simple examples; 3. Breaking RSA encryption with a quantum computer; 4. Searching with a quantum computer; 5. Quantum error correction; 6. Protocols that use just a few Qbits; Appendices; Index.

### Reviews

"...what it treats, it treats extremely well, with rigor and attention to detail that reveals a deep understanding of the subject... "I truly hope that Mermin's book will nurture the next generations of scientists in their understanding of things quantum computational --- or even just plain quantum."
*Barbara Terhal, IBM T.J. Watson Research Center for PHYSICS TODAY*

Pre-Publication Endorsement:

"… will be a standard for instruction and reference for years to come. … The book is suffused with Mermin’s unique knowledge of the history of modern physics, and has some of the most captivating writing to be found in a college textbook."
*David DiVincenzo, IBM T. J. Watson Research Center*

Pre-Publication Endorsement:

"… a gentle introduction to quantum computation especially aimed at an audience of computer scientists and mathematicians. … Mermin has always been an entertaining and comprehensible writer, and continues to be in this book. I expect it to become the definitive introduction to this material for non-physicists."
*Peter Shor, Massachusetts Institute of Technology*

Pre-Publication Endorsement:

"… Mermin’s lucid prose and gentle humor cajole [students] toward a sound intuition for what it all means, not an easy task for a subject superficially so counterintuitive."

*Charles Bennett, IBM T. J. Watson Research Center*

Pre-Publication Endorsement:

"This is one of the finest books in the rapidly growing field of quantum information. Almost every page contains a unique insight or a novel interpretation. David Mermin has once again demonstrated his legendary pedagogical skills to produce a classic." *Lov Grover, Bell Labs*

"The text, the mathematics and the (many, many) circuit diagrams are impeccably laid out; the tone is enthusiastic without resorting to hyperbole; and the writing is clear and a joy to read. Indeed, the reader is well taken care of in this book."
*Wim van Dam, American Scientist*

"...an excellent introductory book..." - James W. Harrinton, Mathematical Reviews