Hidden In Plain Sight 10: How To Program A Quantum Computer

Dr. Thomas takes us on an intriguing journey into the quantum realm in this latest installment of the Hidden in Plain Sight series. The first several chapters are an introduction to quantum mechanics, covering the concept of a quantum state in two-dimensional Hilbert space, the evolution of the quantum state over time, and the action of an operator on a quantum state to reveal a particular eigenstate (i.e., the act of measurement).Following this rather brief review, Dr. Thomas compares Boolian logic, which forms the basis of ordinary, classical computers using bits (0 or 1), with quantum logic using qubits, which can exist in a state superposition (0 and 1). It turns out that Boolian operations are irreversible. For example the input bits of a universal NAND gate cannot be uniquely determined from the single output bit, so Boolian logic thus results in a loss of certainty, which can be equated to an increase in entropy in the forward direction. In contrast, the evolution of a quantum state must be time-reversible (no increase in entropy can occur in the forward direction), restricting the kinds of logic gates that can be used in a quantum computer. Only those gates where the input states can be uniquely determined from the output states, such as the CCNOT gate, can be used. This restriction makes quantum algorithms seem somewhat clumsy compared to their Boolian counterparts, but it becomes clear that this is only a minor disadvantage compared to the huge advantage quantum computation provides in terms of massive parallel processing power, which can increase exponentially with the number of qubits that are employed.The Kindle version of the book provides links to videos prepared by Dr. Thomas, which illustrate how to set up simple quantum algorithms using IBM's on-line 5-qubit simulator. These videos provide extremely valuable demonstrations on how to set up and use this amazing hands-on tool.I've gained a lot more understanding and many more insights about quantum computing from this book than any other sources I've read to date. I must say that the final chapter covering the implementation of Grover's algorithm may prove to be hard to grasp -- it was for me at least-- but otherwise the book is quite suitable for a general audience. I have one small criticism: there are Kindle formatting errors involving exponential expressions like 2^N and 2^64 are shown as 2N and 264. This seems to be a common bug when converting text documents into ePub type format.I highly recommend buying this book. It is quite concise and it can easily be absorbed in a couple of sittings; even so, Dr. Thomas provides all the information necessary to gain a basic understanding of how quantum computers work and an appreciation of their potential power. His entire presentation is in clear, everyday language. Five stars.

The author directs us to the "IBM Quantum Experience" site, but its user-nasty design makes me wonder if IBM should learn basic web development first, and THEN put up a quantum computer site. One irritant after another... do I really have to re-accept the cookies policy every time I log on? Have they heard of the "contact us" concept for people having trouble that is not covered in the FAQ? The browser’s back arrow - what is it for? Apparently IBM does not know. Nothing more irritating than a right-click on back arrow and seeing a drop down populated with a dozen copies of the current page URL, which means you can click forever and you aren’t going anywhere.

Thomas continues with some cool quantum physics writing. This guy knows how to get to the meat, and make the edges of current knowledge seem familiar and comfortable. He is pouring out the pages these days and I did see a little repetition seep into this outing. His editor is obviously having a tough time keeping up with him. The formatting of the exponentials is incorrect, but the true values are clear with a moment's thought.In this book, he shows how Grover's algorithm can search through many possibilities in parallel to find a desired entry among the qubits in superposition. But he also clearly shows why that is essentially useless in practice since the "desired" state must be specially marked. And to know which state should be specially marked requires already knowing the answer. No surprise it's fast when you must have already solved the problem before you can even set up the gates!Of course the setup is faster to give values to quantum experiments than the current state of the art which is simulation at a massive number of lattice points requiring huge piles of calculation. The Grover's probe can be hooked directly to the output of the quantum system to read out the answers--like a high tech voltmeter for reading analog signals. But as a general computer, not yet useful.This explains why Microsoft and IBM are putting their quantum machines online: they are desperately hoping someone from the information theory side will come up with something to make these things relevant for actual algorithms people use.I would also like to correct some of the other reviews that say this book gives you the info to program an online quantum computing simulator: No, the actual quantum computer is online and accepting jobs. Simulators are available, but this book will get you to the point of running programs on actual, extant quantum hardware.

This is a 3 star rating from me while books 1-9 all got 5 stars. I was hoping to come away with understanding the difference between a classical computer and a quantum computer in how the latter can work in parallel due to superposition of its 0s and 1s but I don't really understand this from this book. Sometimes it's hard for a teacher/author to put themselves in a position of not knowing or understanding. I did get the part about our reality being limited to our classical view whereas a truer reality is at the quantum level taking into account superposition.

This is an interesting read. It breaks down some of the 'basic' quantum mechanics into manageable chuncks so you can at least have a conceptually understanding, which is helpful when it comes to understanding Quantum Computing. In fact, most of the book is taken up with this explanation - it is only really in Chapter 8 (of 10) that you get into quantum computing. Thomas covers superposition, Schrodingers equation, complex numbers, entanglement and a bit on the vectors that would be useful if you have no knowledge at all (which is what this book is designed to do to be fair). However, I found the last few chapters a bit of a disappointment - they really don't teach you how to program a quantum computer. What they do allow you to do is copy an existing program and use the IBM Quantum simulator to run a quantum simulation.So, despite the shortfall (IMO) at the end, still recommended as a way to get into the basics of quantum computing.

For a pound on the Kindle, this isn't a bad introduction to the subject of quantum computing but it could be improved. The final sections on programming are a bit sparse and lack enough detail in my opinion. There could also be more info about some of the available gates and it would be nice to give some insight into how superposition and entanglement are implemented in the physical hardware. It might also be interesting to compare the IBM system with an alternative approach such as the D-Wave. The formatting of exponents needs to be fixed asap; using a form such as 2^64 would be simplest. Still, the book is pretty good as a subject taster for the price. It's encouraged me to pick up one of the (cheaper) reference books suggested.

This suffers the same problems that the one on 3D did, though fortunately this one relies more on technological facts. The author comes across as someone knowledgeable who has read up on the topic but who does not have a great depth of understanding. Quantum mechanics is very hard to understand, and this overview is readable enough and has a couple of nice features, so three stars. The nice features are the explanation of quantum logic gates and the links to videos of how to use the IBM publicly accessible quantum computer. If I had already found the latter then quite possibly I would be giving fewer stars here - but such is the quantum-mediated happenstances of life.

This book, and the youtube videos it refers to which have been recorded by the author, offer crystal clear explanations of the concepts behind quantum computing, and how to use the IBM Q quantum computing experience. Given the cost of the kindle book, 99p, its one of the best value for money books I've ever read.

A really great intro into the world of quantum computing that I recommend to anyone starting from nothing. Book can be read cover to cover in about 2-4 hours.