Condensed matter-integral over density of states

  • Thread starter ehrenfest
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  • #1
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condensed matter--integral over density of states

Homework Statement


http://online.physics.uiuc.edu/courses/phys460/fall06/handouts/460-lect12.pdf [Broken]

Could someone explain to me why the first equation on slide 22 is true?


Homework Equations





The Attempt at a Solution

 
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Answers and Replies

  • #2
malawi_glenn
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you mean:

Quantitative evaluation?
 
  • #3
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you mean:

Quantitative evaluation?
What? I mean I don't understand why it is true. It is also on page 142 of Kittel.
 
  • #4
malawi_glenn
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What? I mean I don't understand why it is true. It is also on page 142 of Kittel.
Oki I just mean the eq under that headline.

any way here it goes:

take eq 24 on p 142. and read the 3lines above it.

What is the fermi dirac distribution at T = 0K? well f (T goes to 0) = 1.. (see eq 5 p.136 and take limit t goes to 0).

and you only have to integrate up to the fermi energy at 0K due to the density of state function. see fig 5 p.140.
 
  • #5
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Oki I just mean the eq under that headline.
What is the fermi dirac distribution at T = 0K? well f (T goes to 0) = 1.. (see eq 5 p.136 and take limit t goes to 0).
f (T goes to 0) = 1 only if mu > epsilon
 
  • #6
malawi_glenn
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Oh yes, it meant when kT << E_f

:)
 
  • #7
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Oh yes, it meant when kT << E_f

:)
Why does that imply that mu is greater than epsilon?
 
  • #8
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Oki I just mean the eq under that headline.
Oh--yes it is the equation under that headline--sorry.
 
  • #9
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see fig 5 p.140.
I see,the area of region 1 must be the same as the area of region 2.
 

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