Title of article :
Elementary energy bands in crystals are connected
Author/Authors :
Michel، نويسنده , , L. and Zak، نويسنده , , J.، نويسنده ,
Abstract :
A short review is given of elementary band representations of space groups and correspondingly a definition is presented of elementary energy bands in solids. Using these notions one can conclude that all the branches of an elementary energy band are connected. We present in this chapter a topologically unavoidable degeneracy in the band structure of solids.
Keywords :
infinite groups , general topology , Narrow band systems
Journal title :
Astroparticle Physics
