I just finished Coursera’s Exploring Quantum Physics. It was pretty good: the Coursera Web sites works well, both lectures and homework exercises were good and the discussion forums were helpful.
The course starts from the basics, but it is not an introductory course: it requires a decent mathematical background (linear algebra and calculus, Fourier transforms) and some previous knowledge of quantum physics is useful, although not strictly necessary.
The course is taught by two teachers with very different styles covering quite different material, this makes it a bit disjointed. I would have preferred a single teacher thorough the whole course.
The program covers various advanced subjects like the Feynman path integral, quantum localization, superconductivity, the Dirac equation, the time-dependent Schrodinger equation and so on. The problem is that having to start more or less from the basics it is impossible to cover any of these advanced subjects in any detail: they are just introduced but not explained enough to get a real understanding. I think it would be better to limit the course to the more ‘standard’ introductory stuff, with maybe just one or two advanced topics covered in more details.
Through a post in one of the Coursera’s forum I discovered the ‘Theoretical minimum’ Stanford lectures. It is not a course but just a collection of live lectures by the same professor. I watched a couple of them on quantum field theory, the first particle physics series and now I am watching the quantum entanglement ones.
The lectures are for a general audience, so they usually start from the very basics and then build the whole theory step by step. The teacher – professor Susskind – manages to introduce very complex stuff in an approachable way.
Being live lectures, there tend to be quite a lot of question from the audience, backtracking and interruptions – these makes them much longer that the recorded Coursera lectures, but I found that this makes the material more easily absorbed (by me at least).
They are very good introduction to modern physics for anyone with some scientific background and enough time to watch an entire series: watching individual lectures would probably not work.