A Modern Approach to Quantum Mechanics

by John S. Townsend

Inspired by Richard Feynman and J.J. Sakurai, A Modern Approach to Quantum Mechanics allows lecturers to expose their undergraduates to Feynman's approach to quantum mechanics while simultaneously giving them a textbook that is well-ordered, logical and pedagogically sound. This book covers all the topics that are typically presented in a standard upper-level course in quantum mechanics, but its teaching approach is new. Rather than organizing his book according to the historical development of the field and jumping into a mathematical discussion of wave mechanics, Townsend begins his book with the quantum mechanics of spin. Thus, the first five chapters of the book succeed in laying out the fundamentals of quantum mechanics with little or no wave mechanics, so the physics is not obscured by mathematics. Starting with spin systems it gives students straightfoward examples of the structure of quantum mechanics. When wave mechanics is introduced later, students should perceive it correctly as only one aspect of quantum mechanics and not the core of the subject.

Genres: Physics, Science, Quantum Mechanics, Textbooks, Nonfiction, Stem, Mathematics

476 pages, Hardcover

First published March 1, 1992

Reviews

[Sean · Rating 5 out of 5]

One of the few texts I can honestly say I have spent serious time staring at, front to back. Good times.

[Warren Rogers · Rating 4 out of 5]

This is an excellent undergraduate text in quantum mechanics. I learned quantum mechanics from John Townsend at Harvey Mudd College. He is an excellent instructor in a complex and challenging topic, and I love that the book reminds me so much of my days as his student. I have adopted it as the text in my own year-long quantum mechanics course and find that students like it and benefit from its strong pedagogical and friendly writing style.

[Karthik Boyareddygari · Rating 4 out of 5]

The content is more or less all there between the text and the exercises, but there are times when the student must make pretty large leaps in the exercises from what was covered in the text. With time, I came to appreciate because it pushes the right kind of student to learn better than they otherwise would have. Also, the text often comes across as doing little math tricks to advance the theory, but it tries to give intuition wherever possible when developing the theory. Setting the foundation with Dirac bra-ket notation and linear algebra/matrix mechanics over wave functions actually appeal a lot to me, and it helped make superposition, observables, operators, etc. make a lot more sense. The appropriate escalation from here would be to Shankar.

[Allen · Rating 5 out of 5]

I prefer the matrix-based approach to Quantum Mechanics over the calculus-based Griffiths, because it introduces the mathematical structure that become useful for further physics. Innovative and enjoyable approach.

[Stephen Fay · Rating 4 out of 5]

Solid

[Alek Elbekian · Rating 5 out of 5]

Simply the best for an intermediate qm course

[Nattapon Chotsisuparat · Rating 5 out of 5]

for advanced undergrad or grad students

[Elena · Rating 4 out of 5]

genial explicada la física cuántica 👌👌👌👌👌

[Tue Le · Rating 4 out of 5]

This is not an outstanding book like "Introduction to Electrodynamics" by Griffiths. Perhaps this is due to the frankly bizarre framework that is quantum mechanics. However, it is a fine textbook that guides the students through a knotty subject. Instead of throwing the Schrodinger equation at the student right from the start, Townsend begins, like Sakurai does, with the Stern-Gerlach experiments, which reveal the quantization of electronic spin. Using this as an example, Townsend unveils the mathematical structure of quantum mechanics, that is, an eigenvalue problem. From there, he builds up the subject in a logically coherent manner. The Schrodinger equation and the Heisenberg equation of motion (4.16) are all derived from axioms for operators in Hilbert space. This seems rather abstract, but is actually more insightful and fruitful than starting with wave mechanics, which could give the false impression of quantum mechanics being the familiar phenomena of wave propagation. In later chapters, one learns how to handle some canonical cases, namely the simple harmonic oscillator and the two-body problem with the Newtonian/Coulombic potential. Perturbation theory is then treated. Further advanced topics are discussed for those with the time.

In all, this is a decent book for advanced undergraduates.

[Jonathan · Rating 3 out of 5]

Makes a difficult subject very accessible. I still hold a grudge that he didn't give me an attribution somewhere for the section on quantum computing though. Giving me props in class does not do justice. :P

[Ryan · Rating 4 out of 5]

Good introduction to QM using the first few chapters to discuss statistical concepts and matrix mathematics. This book is a great working guide to solving QM problems focused almost entirely on use of Dirac notation. Very comprehensive introduction to perturbation theory.

[Charlie Wu · Rating 3 out of 5]

Sakurai for undergrads

[Brendan]

No glossary or index, but a great textbook