Crystal momentum

In solid-state physics, crystal momentum or quasimomentum is a momentum-like vector associated with electrons in a crystal lattice. It is defined by the associated wave vectors ${\displaystyle \mathbf {k} }$ of this lattice, according to $${\displaystyle \mathbf {p} _{\text{crystal}}\equiv \hbar \mathbf {k} }$$ (where ${\displaystyle \hbar }$ is the reduced Planck constant). In systems with discrete translation symmetry, crystal momentum is conserved like mechanical momentum, making it useful to physicists and materials scientists as an analytical tool.