# Fermi impulse

The Fermi momentum is the momentum that corresponds to the Fermi energy : ${\ displaystyle p _ {\ text {F}}}$ ${\ displaystyle E _ {\ text {F}}}$

${\ displaystyle p _ {\ text {F}} = \ hbar k _ {\ text {F}} = {\ sqrt {2mE_ {F}}}}$

with . ${\ displaystyle k _ {\ text {F}} ^ {2} = {\ frac {2mE_ {F}} {\ hbar ^ {2}}} \ Leftrightarrow k _ {\ text {F}} = {\ frac {\ sqrt {2mE_ {F}}} {\ hbar}}}$

In the case of K , the maximum momentum of the most energetic electron is in a solid. In the momentum space one can define the Fermi sphere , which has the radius and thus contains all existing electron pulses. ${\ displaystyle T = 0}$ ${\ displaystyle p _ {\ text {F}}}$${\ displaystyle p _ {\ text {F}}}$

## literature

• Neil W. Ashcroft, N. David Mermin: Solid State Physics . 2nd Edition. Oldenbourg, Munich 2005, ISBN 3-486-57720-4 .