Quantum Computing for Everyone (Mit Press)

Despite being around for decades, the words “quantum mechanics” still make eyes roll even in a room of educated people. Few really understand the phenomena. Among those more scientifically minded, some – thankfully fewer in number – still argue that quantum mechanics will give way someday to a more classical approach. The controversial part of quantum mechanics, which foiled even Albert Einstein, states that to measure the spin or velocity of an electron, one must interfere with the system permanently. This enmeshment of the measurer with the system confuses people, but numerous experiments highlight this paradox. It seems to be an innate part of the universe, not merely a technological limitation. Smart physicists and mathematicians have noticed an opportunity around quantum mechanics: We can address computational questions with its approach. A system of “qubits” can be used to address problems that classical computing cannot address. This observation has produced a new scientific field of quantum computing. Recently, major companies have begun to jump into this technology in a quest for early supremacy. Most textbooks use a lot of math to introduce quantum computing – rightfully so because mathematics provide the basis towards all computation. But a math-heavy approach makes the field relatively inaccessible. To address this shortcoming, Chris Bernhardt provides an introduction to the subject with less mathematics. The book teaches basic linear algebra needed to approach the subject. It’s still heavy on the words, not the mathematics, and draws out applications and challenges that confront the field. Since a child, I have loved mathematics and its creative expressivity. I enjoyed how Bernhardt introduced me to relevant concepts and drew me into quantum concepts. By the end of the book, however, I glazed over the mathematics in favor of just getting the book completed. Perhaps that is a personal failing, but it’s one that I witnessed in many of my college math classes, too! I found the next-to-last chapter on quantum algorithms the least accessible, but the last chapter on quantum applications was the most interesting. Those in the investment community can find a deep dive into this topic helpful to carefully discover future winners and losers in this burgeoning field. Quantum computing presently requires a lot of money to access, but presumably, like classical computing, that cost will go down with time. This field is fascinating to think about, and Bernhardt makes it truly accessible “for (almost) everyone.”

I found Bernhardt's book to be both an extremely accessible and rigorous introduction to quantum computing. The writing is very good and the book has elements of a good story with one topic feeding well into the next. One unusual feature of the book is that it treats quantum computing over the reals rather than the complex numbers, with indications here and there how things would be different over the complex numbers. The book starts off with a nice account of the Stern-Gerlach experiment to explain spin, mentioning how the same conclusions can be arrived at simply by using polarised filters and ordinary light. There is then a self-contained chapter on linear algebra as a physicist sees it, using bras and kets. The book then progresses to talk about qubits, entanglement, and a host of other topics. The topics I enjoyed most were the following: (i) The description of the BB84 protocol for determining if someone is eavesdropping on a communication line, (ii) the description of entanglement, including physical means of entangling qubits (though I supplemented the material with information from the Internet), (iii) the discussion of Bell's Theorem, Einstein's views and hidden variables (again I supplemented with information from the Internet), (iv) the discussion of quantum gates, (v) the no cloning theorem, (vi) quantum teleportation and (vii) the discussion of the Deutsch, Deutsch-Jozsa and Simon problems and algorithms. The coverage of Shor's and Grover's algorithms were too sketchy for me to follow well. Perhaps a sequel will cover these more rigorously. All in all a very lucid and enjoyable intro to quantum computing that I recommend highly!

Quanting computing for everyone provides a readable introduction to the mathematical structure of computing with qubits. The author does a fine job of introducing a challenging subject to the reader, and by using only real coefficients for quantum states, does a novel job of smoothing over the complexities of phase. The level is around the same as the author's other work "Turing's Vision", and is approachable but has its challenges and there are certain parts where the uninitiated will have to gloss over and perhaps return or just try to absorb the big picture concept. The book is split into 9 chapters and the first 6 are the most readable. The first chapter where the author describes spin includes a practical experiment anyone can do with polarized filters that displays the remarkable consequences of quantum mechanics and measurement. The author then gets into linear algebra and its use in formalizing the structure of quantum mechanics. I think the author does a great job of guiding the reader through a deep subject with concrete examples of how was switches basis, what it means and row and column space. The author then goes back to quantum mechanics and discusses qubits and how spin 1/2 particles can encode qubits. The author gets into privacy experiments with the infamous Alice, Bob and Eve to illustrate how encryption scenarios are described. The author then tackles the profound issues of entanglement and measurement. In particular the author introduces the reader to tensor product spaces and the construction of entangled states that cannot be a combination of individual particle basis states. The author is able to introduce Bell's inequality and non-locality which is a feat in itself as it is a remarkable result and the author does it with just using real coefficients for a 3 particle system. The author then moves on to basic circuit logic and the construction of universal gates. Boolean logic is of course discussed as well as how one can build functions from logic gates. The author introduces concepts like reversible computation and brings up that one can compute with analog machines set up in appropriate initial conditions and the concept of computation flows far outside of traditional computer science and into the realm of physics. The material starts to get challenging when he starts to describe quantum gates and computation. Though the material is self contained it is not the easiest to follow as ideas start to build through layers of logic. Finally the author gets into how one can use quantum algorithms to solve NP problems for efficiently than is currently possible through classical algorithms. He discusses the wave of innovation in ideas in quantum computing in the 80s and introduces Shor's algorithm but at a high level given how involved some of the properties are. Overall Quantum Computing for Everyone is readable but challenging. I think a variety of readers can get something out of the book. I think it unlikely that one has the ability to use this book to become well acquainted with the subject but it can be used to get a sense of the ideas and it can be used by those well versed to get some intuitive communication about ideas they already know. Definitely worth trying to go through for those interested in the subject and could be read as supplemental to a text book for those looking for both substance and intuition.

Really fascinating book, great attempt to make an exotic field accessible to a broad audience and a great introduction to and explanation of both quantum physics and quantum computing. The maths are however still very present (as they are essential to the explanation itself) and - although well explained - not to be underestimated. Having studied quite some maths and had an intro course in quantum physics I can follow everything rather well, but cannot guarantee it would be the same for everyone.

Es un libro relativamente breve que hace lo posible para simplificar las matemáticas de algo no trivial como la mecánica cuántica. Enseña algunos algoritmos de ejemplo para que se entienda el potencial. El libro ha escogido ser breve, conciso y atemporal centrándose en : - Principios básicos de computación cuántica - Algortimos de ejemplo - La mínima matemática y física necesaria Lo que no es: - Un libro de mecánica cuántica - Un libro sobre el estado del hardware. Eso es algo que posiblemente cambie en cada momento - Un manual de física - Un libro de referencia con toda la matemática y todos los posibles algoritmos con el estado del arte Debo decir que yo parto de una formación de ingeniería que ya había dado mecánica cuántica en la carrera hace más de una década.

This book provides a nice entry point for people interested in quantum computing. While some parts of the book could have been more in depth, it was never the intention of the author to overwhelm the readers with complex technical details, but to provide them with the necessary tools, knowledge and historical background to explore more advanced books and resources on quantum computing. While this book is aimed toward "everyone", basic knowledge in mathematics (linear algebra), physics and computer science/electrical engineering (for the logic gates) is a must-have to easily understand the ideas behind quantum computing presented by Chris Bernhardt. Overall, a great experience that I recommend to anyone interested in this topic and looking for a starting point.

I am satisfied with the purchase and highly recommend it! An important note is that knowledge of mathematics (linear functions) is required to understand it. The product itself is excellent.

quantum computing is explained from very basics and is very well explained