David Park - Introduction to the Quantum Theory

This is a first course in quantum mechanics, but students will find it easier if they have had some exposure to experimental facts and basic quantum-mechanical terminology, at the modern physics level, before they start it. Otherwise it is fairly self-contained, with covering mathematical topics and the essentials of electromagnetic theory to help make it so.

For flexibility of use, the book is divided in two parts: the first on basic theory and the second on selected applications. There is no intention that are supposed to show what one actually does with the theory, how the numbers come out, and what they have to do with experiment.

In teaching from a book of this length there is always the question of what to omit. To facilitate the choice, sections of that contain the essential physical argument are marked with , but I think that a course covering only this material would be a pretty dull one. At the other extreme, there are a few sections marked with o that would not be covered in a conventional course and are included essentially for fun.

The text contains many problems in which steps of the proofs and related ideas are explored. They vary in difficulty; some are trivial while a few others point toward voyages of discovery. Some are numerical, and students should be able to do them. A few use a computer. gives a simple program for integrating a second-order differential equation.

The units are SI, with the exception that e2/40 is usually abbreviated e2. It makes quicker writing in most situations, and if one needs to calculate a transition probability or a susceptibility one can easily reinstate the e.

This edition omits two chapters that were in the old ones, those on thermodynamics and statistical mechanics, since there are now several good introductory texts to choose from. It also adds two chapters. most working physicists took a rather dismissive view of these questions, assuming that as science progressed they would all disappear or become irrelevant. Neither of these has happened. Instead, experimental techniques have already progressed to the stage where people are experimenting with a few atoms, or one at a time, and measuring effects in which only one or two quanta are exchanged with the measuring apparatus. This means that the old Copenhagen interpretation, which described the apparatus classically, is no longer adequate, and new explanatory structures must be set up. Since there are also well-known phenomena that manifest quantum nonseparability on the macroscopic scale, it seemed appropriate to put in a chapter which, if it does not answer any of the deep methodological questions that arise, at least discusses them.

, Classical Dynamics and Feynmans Construction, is also new. It seemed to be required because this method is used in an essential way in so much of modern theory. The chapter is self-contained and can be omitted without loss of continuity.

I must thank my colleagues in the Physics Department at Williams College for answering questions that must have seemed naive, and for providing, year after year, an atmosphere of friendly cooperation.

McGraw-Hill and I would like to thank the following reviewers for their many helpful comments and suggestions: Glenn Agnolet, Texas A&M University; Karamjeet Arya, San Jose State University; Bill Dalton, St. Cloud State University; Michael Grady, SUNY, Fredonia; Richard Hazeltine, University of Texas; and Jack Mochel, University of Illinois, Urbana-Champaign.

David Park