Buying my first Quantum mechanics book

[Hamiltonian]

I recently started studying some quantum mechanics, so far I have been using online resources(like MIT OCW 8.04/8.05, and Tongs notes I think I have reached a stage where I understand the Schrödinger eqn and can solve it for various potentials(including for the H-atom) but I don't know anything about things like scattering, perturbation theory, quantum dynamics$V(r,t)$ etc.) I now feel like buying a book on the subject.
Griffiths QM is usually recommended for a newbie like me, but lots of people also say that the book isn't that good and doesn't live up to the standards set by Griffiths E&M. David Bohm's book is also meant for beginners (it is a relatively cheap book) and then finally there is Townsend's QM. I have heard Sakurai's book is like the holy bible for QM, but I think that's way too advance for me right now.

any recommendations as to which book I should go with from the ones listed above(or any other ones that you think might be a good fit)?

 

[PeroK]

I liked Griffiths' book, but I'm not familiar with the alternatives.

Sakurai's book is excellent and develops QM using a more abstract approach to the formalism. If you've mastered wave mechanics, then you are probably ready for Sakurai. Although, the alternative is to press ahead with scattering and perturbation theory.

 

[andresB]

If you already solved the Schrödinger for various potentials, then you need some bra-kets in your life. Of all the good books, the one that is just at the right level and covers enough material is Cohen-Tannoudji.

 

[Frabjous]

An oldie, but reasonably priced goody is Messiah.

I would suggest reading the section on solving a specific potential that you already know in each of the books that sound interesting to you and picking the one whose treatment resonates best with you.

 

[andresB]

An oldie, but reasonably priced goody is Messiah.

I would suggest reading the section on solving a specific potential that you already know in each of the books that sound interesting to you and picking the one whose treatment resonates best with you.

I jumped from Griffiths to Messiah because they were the only books available (3rd world problems), and I think Messiah was unnecessary hard for that level. Don't get me wrong, I still read and use that book, the Dover edition is a gem.

 

[Frabjous]

I jumped from Griffiths to Messiah because they were the only books available (3rd world problems), and I think Messiah was unnecessary hard for that level. Don't get me wrong, I still read and use that book, the Dover edition is a gem.

I do not dispute that Messiah is an ambitious choice which is part of the reason I suggested the OP read a section (the other being that different books speak to different people). It was my backup book for undergraduate and first year graduate quantum.

 

[andresB]

Well, Messiah does have one big advantage over Cohen-Tannoudji, The Dover edition is quite cheap in comparison.

 

[Frabjous]

Well, Messiah does have one big advantage over Cohen-Tannoudji, The Dover edition is quite cheap in comparison.

I am not saying that it is not a good book, but Cohen-Tannoudji always left me cold.

 

[Frabjous]

This thread has a couple of suggestions
https://www.physicsforums.com/threads/alternative-undergraduate-quantum-mechanics-book.979608/

 

[paralleltransport]

I strongly disagree. I think Griffiths book is a really good way to learn quantum mechanics the first time. It does a good job teaching perturbation theory (both non-degenerate and degenerate), and scattering theory as well as most advanced topics like geometric phase (adiabatic approximation). At the same time it doesn't overwhelm you with details. Note that griffiths is the official textbook for MIT's Quantum sequence (8.05/8.06 = Quantum II/ Quantum III).

I had nothing but griffiths and after a summer of intense study i was able to do quantum field theory after it.

By the way if you want to know perturbation theory, just study the continuation of the MIT course online (you said you studied 8.04/8.05):
https://ocw.mit.edu/courses/physics/8-06-quantum-physics-iii-spring-2018/

8.05 covers the fundamental formalism and simple systems. 8.06 covers approximation techniques (perturbation theory and scattering).

It has both lectures and lecture notes. What else do you need :)?

 

[vanhees71]

Well, I don't know anybody using Griffiths at all personally, but from the postings of usually confused students in this forum I can often correctly guess that they read Griffiths's book, and when asking where the confusion comes from it's often confirmed ;-). I think Griffiths is in some points too sloppy with the math, which leads to confusion. Of course you can also be too rigid with the math on an introductory level, and then all the mind-boggling physics is hidden behind a "math wall". It's very difficult to find the right balance. One book, I think has it right is Sakurai (the revised edition co-authored/completed by Tuan; the later edition with Napolitano is also good but contains some additional "relativistic QM", which I think is outdated, and one should teach relativstic as QFT from the beginning).

 

[Dr Transport]

I think Griffiths is in some points too sloppy with the math

I find that Griffiths is sloppy with the math in ALL of his texts, not just his QM text.

 

[paralleltransport]

Well, I don't know anybody using Griffiths at all personally, but from the postings of usually confused students in this forum I can often correctly guess that they read Griffiths's book, and when asking where the confusion comes from it's often confirmed ;-). I think Griffiths is in some points too sloppy with the math, which leads to confusion. Of course you can also be too rigid with the math on an introductory level, and then all the mind-boggling physics is hidden behind a "math wall". It's very difficult to find the right balance. One book, I think has it right is Sakurai (the revised edition co-authored/completed by Tuan; the later edition with Napolitano is also good but contains some additional "relativistic QM", which I think is outdated, and one should teach relativstic as QFT from the beginning).

I'd say most QM texts are sloppy with the math for good reasons: it's easier the first time to be sloppy and be able to calculate things and leave the proofs to mathematicians. If you're struggling trying to understand basic bra ket notation, the last thing you want is for someone to throw functional analysis at you. Furthermore you'll have to get used to non-rigorous math if you'll do more advanced physics. One example is QFT books are even more sloppy with the math than QM books, since the math hasn't yet been invented to describe it rigorously.

I never had to think about subtleties of the theory of distributions or generalized functions in my intro QM course, and the math underlying quantum (functional analysis) is not mentioned at all, even in sakurai which is the standard graduate text.

 

[vanhees71]

Of course, all QM texts are sloppy with the math since they are textbooks addressed to physicists and not mathematicians. For them there are more special textbooks, and it's worthwhile to study them also for physicists after having an idea what QM is about from a physics point of view. However, you can overdo the sloppiness, making QM even more difficult to learn than with the right amount of rigor, and imho Griffiths text is beyond the level of sloppiness such that it leads to confusion.

Some of the subtleties of unbound operators, e.g., should be treated also correctly in a intro physicists'-level textbook. E.g., I know only 2 books, which correctly argue, why orbital angular momentum provides only integer-valued quantum numbers and not half-integer numbers... The one-line argument about uniqueness of the wave function is misleading since overall phase factors are unimportant, and the wave function doesn't need to be a unique function of the spacetime argument but only modulo a phase factor.

 

[Hamiltonian]

imho Griffiths text is beyond the level of sloppiness such that it leads to confusion.

I actually ended up buying Griffth's

Pretty happy with it so far, I am accompanying it with David Tong's notes and The 8.04/8.05 lectures