solid-state physics

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun The branch of condensed matter physics that deals with the physical properties of solids, especially the electromagnetic, thermodynamic, and structural properties of crystalline solids, such as semiconductors.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun the branch of physics that studies the properties of materials in the solid state: electrical conduction in crystals of semiconductors and metals; superconductivity; photoconductivity