LAUSR

This is an unusual textbook, for two reasons. First, any attempt to cover both quantum physics and special relativity in a self-contained manner within a book less than 300 pages long is audacious. Second, one of the authors’ main goals of this text is to ‘convey how quantumphysics and relativity form an important part of our cultural and intellectual heritage’ – in the context of a physics textbook, this is a peculiar choice of words. I definitely agree with the authors, this textbook is unique. Let me first begin by clearly stating that the authors have done an exceptional job. It’s probably more accurate to describe this text as an introduction to both non-relativistic and relativistic quantum mechanics (QM). Indeed, the first half of the book is devoted to non-relativistic QM, followed by a single chapter on Special Relativity. The second half of the book content primarily consists of relativistic corrections to QM (fine structure, etc.) and a final chapter on ‘Entanglement’. The scope of this textbook is dizzying, to say the least. For example, two-level systems are covered in barely more than a single page, and a free particle given half that amount of space. Quantum field theory is disposed of in 4 pages. This is the price paid to keep the textbook length below 300 pages. It’s not entirely clear who the audience for this textbook is. Clearly, this book could form the basis for a ‘Physics III’ or ‘Modern Physics’ course, but it could also serve as the sourcebook for an introductory QM course. I would be very cautious about using this book as a self-study text for reasons that I will explain shortly. Personally, I would be likely to use this textbook as a supplement. The authors’ idiosyncratic approach provides brief discussions of several topics I would like to touch on in my own QM courses: cold matter and entanglement purification, for example. I also greatly appreciate the occasional use of thermodynamic arguments to obtain results—an approach rarely encountered in other QM texts. Having (too) brief sectionsmeans that I can easily find ‘refresher’ discussions about nearly every topic I cover in a 2-semester QM course. Lastly, the example problems provided at the end of each chapter (and answers provided at the end of the book, in Chapter 13) span a useful range of difficulty. Now for my concern. I want to be clear: in my experience, QM textbooks reflect a far wider range of idiosyncratic approaches than any other branch of science. This is not inherently bad. My concern is the varying level of mathematical sophistication employed. Certainly, the first four chapters are at a level typically associated with introductoryQM: basic calculus and a single differential equation (Schroedinger’s). However, in Chapter 8 (‘Formal structure of QM’), Dirac notation suddenly appears along with the attendant body of linear algebra. Operators are introduced as needed, without any real systematic discussion: raising and lowering operators appear in Chapter 4, well before any notion of linear algebra has been discussed. If there is a knowledgable instructor who can help guide the students, this is less of a concern. However, it does limit the self-study capability of this book. Regardless, this book was a lot of fun to read and digest. I definitely recommend it for instructors, but also for students who have already been exposed toQM.Kudos to the authors for pulling off such an audacious feat.