This LibreTexts book does have some interest!
100 10-20 minute videos properly split by topic, good resource!
Instructor: Barton Zwiebach.
Free material from university courses:
- physics.weber.edu/schroeder/quantum/QuantumBook.pdf (archive) "Notes on Quantum Mechanics" pusbliehd by Daniel V. Schroeder (2019) The author is from from Weber State University.
Author: David Tong.
- Chapter 2 "Band Structure" covers electronic band theory
Looks very impressive! Last update marked 2011 as of 2020.
Goes up to "A.15 quantum field theory in a Nanoshell", Ciro have to review it to see if there's anything worthwhile in that section.
Personal page says he retired as of 2020: www.eng.fsu.edu/~dommelen/ But hopefully he has more time for these notes!
For the UCSD Physics 130 course.
Last updated: 2013.
Very good! Goes up to the Dirac equation.