The Wave Vector is Limited from Below

Abstract

It is shown that the electron wave vector in a crystal cannot be smaller than a certain value. As a result, in a crystal there are many first Brillouin zones, and not only one as it had been supposed earlier. In crystal there can be many electrons with the same wave vector, and not only two as it had been supposed earlier. These electrons must be at sufficiently large distances from each other. An attempt is made to explain the decrease of electric and thermal conductivity with decreasing crystal size.