Editing Fermi gas (section)

==Related Fermi quantities==
Related to the Fermi energy, a few useful quantities also occur often in modern literature.

The '''Fermi temperature''' is defined as <math display="inline">T_{\mathrm{F}} = \frac{E_{\mathrm{F}}}{k_{\rm B}} </math>, where <math>k_{\rm B}</math> is the [[Boltzmann constant]]. The Fermi temperature can be thought of as the temperature at which thermal effects are comparable to quantum effects associated with Fermi statistics.<ref>{{cite web|title=PHYS 3700: Introduction to Quantum Statistical Thermodynamics|url=http://www.physics.usu.edu/torre/3700_Spring_2015/Lectures/08.pdf|last=Torre|first=Charles|date=2015-04-21|website=Utah State University|access-date=2018-03-21}}</ref> The Fermi temperature for a metal is a couple of orders of magnitude above room temperature. Other quantities defined in this context are '''Fermi momentum''' <math display="inline"> p_{\mathrm{F}} = \sqrt{2 m E_{\mathrm{F}}} </math>, and '''Fermi velocity'''<ref>{{cite web|title=Fermi level and Fermi function|url=http://hyperphysics.phy-astr.gsu.edu/hbase/Solids/Fermi.html|last=Nave|first=Rod|publisher=[[HyperPhysics]]|access-date=2018-03-21}}</ref> <math display="inline"> v_{\mathrm{F}} = \frac{p_{\mathrm{F}}}{m}</math>, which are the [[momentum]] and [[group velocity]], respectively, of a [[fermion]] at the [[Fermi surface]]. The Fermi momentum can also be described as <math>p_{\mathrm{F}} = \hbar k_{\mathrm{F}} </math>, where <math>k_{\mathrm{F}}</math> is the radius of the Fermi sphere and is called the '''Fermi wave vector'''.<ref>{{cite book|last1=Ashcroft|first1=Neil W.|url=https://archive.org/details/solidstatephysic00ashc|title=Solid State Physics|last2=Mermin|first2=N. David|publisher=[[Henry Holt and Company|Holt, Rinehart and Winston]]|year=1976|isbn=978-0-03-083993-1|url-access=registration}}</ref>

Note that these quantities are ''not'' well-defined in cases where the Fermi surface is non-spherical.