Academic Resources 

1) https://arxiv.org/

2) https://www.condmatjclub.org/

Some classic textbooks on Condensed Matter Theory:

1) Condensed Matter Field Theory by Alexander Altland, ‎Ben D. Simons.

2) Many-Body Quantum Theory in Condensed Matter Physics by Henrik Bruus, ‎Karsten Flensburg.

3) Quantum Field Theory and Condensed Matter: An Introduction by Ramamurti Shankar.

4) Basic Notions Of Condensed Matter Physics by Philip W. Anderson.

5) Many-Particle Physics by Gerald D. Mahan.

6) Quantum Theory of Many Particle Systems by Fetter & Walecka.