# Momentum and indirect bandgap

When an electron is excited from valence band to conduction band, it has to have a finite momentum in the case of indirect bandgap. Does that mean that the electron cannot be created at rest ? does it have a non zero "speed" ?

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In general case $v\equiv\dot{q}=\frac{\partial H}{\partial p}$ which leads to $\dot{q}=p/m$ only if $H=\frac{p^2}{2m}+U(q)$ –  Misha Oct 23 '11 at 9:24