Quantum Physics

Abstract

The authors of this textbook are two experimental physicists working in condensed matter who state that they wrote it looking for a pragmatic approach. With this premise the book could be expected to concentrate on the applications at the expense of the principles. This is not the case, however, the authors having achieved a good balance. The text is intended for the second part of a degree course, assuming that the students have a good grasp of calculus and classical physics, especially of classical mechanics and electromagnetism, and that they have some familiarity with the main ideas of modern physics. For that level, the book can be described as advanced but not as excessive. The first five chapters, covering 200 pages out of the total of 474, are devoted to the postulates, which could seem too much for a pragmatic approach. But the authors have chosen to present the mathematical background and the physical consequences of quantum mechanics as soon as possible in association with the postulates. It is their way to reach a balance between principles and applications. Although they rely on intuition, they care for the precision and develop the calculation with detail. This, their effort to relate the applications to the postulates, is perhaps the most valuable aspect of the book. In my opinion, the method works. For instance, the Heisenberg relations are introduced following the first postulate, before presenting the idea of an operator associated with a dynamical variable, with a description of the Fourier transform, although explaining with care the idea of uncertainty. The concepts of Hermitian and unitary operators are introduced in two examples in the chapter on the second postulate, and so on. Although some physicists would prefer a more clear-cut separation between mathematical prerequisites, postulates and consequences, especially the theorists (of whom I am one), the book will certainly be effective and suitable for general students. The second part develops the applications of the postulates to physical problems, with chapters on one-electron atoms, angular momentum, approximate methods, many-particle systems, and atomic and nuclear radiation. The book contain a good number of exercises and problems, carefully solved in detail, which should allow the students to do their homework with useful assistance. To summarise: this is a good and recommended textbook for a course on quantum physics, intended for a pragmatic preparation to the study of atoms, nuclei or condensed matter. It could be suitable also as a first introduction, prior to deeper analysis, for those who aim to understand later the frontiers of quantum theory itself.