Condensed matter physics is the study of how enormous numbers of particles conspire to produce the properties of solids and liquids, from ordinary conductivity to superconductivity and beyond. It is the largest branch of physics by headcount, and its books span from crystalline fundamentals to the field-theoretic machinery needed for its most interesting phenomena. Order matters because each level of abstraction assumes the last.
The natural arc is single-particle physics in periodic solids first, then the many-body methods that describe electrons interacting, then the modern topological ideas that reorganized the whole field. Skip the middle and the frontier reads like incantation.
Master solid-state fundamentals
Solid state physics by Neil Ashcroft and David Mermin is the beloved standard, thorough and physically motivated on crystals, electrons in periodic potentials, phonons, and transport. Read it as your spine. Introduction to solid state physics by Charles Kittel is the other classic, broader in coverage and useful for a second perspective on any topic.
Learn the many-body machinery
Interacting electrons need field-theoretic tools. Quantum theory of many-particle systems by Alexander Fetter and John Walecka is the readable introduction to second quantization and Green's functions, and Many-particle physics by Gerald Mahan is the comprehensive reference for the same methods applied to real problems. Condensed Matter Field Theory by Alexander Altland and Ben Simons brings a modern path-integral perspective, and Quantum field theory in condensed matter physics by Alexei Tsvelik sharpens the field-theory viewpoint further.
Reach the modern frontier
The Theory of Superconductivity in the High-Tc Cuprates by Philip Anderson captures one of the field's central puzzles from a founding voice. Strongly Correlated Systems edited by Adolfo Avella and Ferdinando Mancini surveys where the many-body methods are pushed hardest. Then the topological revolution: Topological Insulators and Topological Superconductors by B. Andrei Bernevig and Topological Phases of Matter by Roderich Moessner and Joel Moore show how topology reshaped our picture of quantum matter.
Read in this order and the frontier stays connected to the ground. Follow the full path to keep the climb continuous.
