Learning solid-state physics requires a certain degree of maturity, since it involvestying together diverse concepts from many areas of physics. The objective is to understand, in a basic way,
how solid materials behave. To do this one needs both a good physical and mathematical background. One definition of .solid-state physics is that it is the study of the physical (e,g. the
electrical, dielectric, magnetic, elastic, and thermal) properties of solids in terms of basic physical laws. In one sense, solid-state physics is more like chemistry than some other branches
of physics because it focuses on common properties of large classes of materials. It is typical that solid-state physics emphasizes how physical properties link to the electronic structure. In
this book we will emphasize crystalline solids (which are periodic 3D arrays of atoms).