Reddit mentions of Condensed Matter Field Theory

Usually papers aren't the best way to start learning about a topic unless you're already pretty advanced in the field. It would probably be a good idea to get a textbook on condensed matter theory to start with, then once you're comfortable with the treatment of the topic in there you'll be better prepared to understand the papers. I suggest Altland and Simon's Condensed Matter Field Theory. Its a pretty great book to start learning from for most topics in condensed matter theory (plus it uses functional integral methods right from the start) and, unlike many other more expensive books that I've seen, it has a section devoted to topological states.