Potential and impurities

  • Thread starter Niles
  • Start date
  • #1
1,868
0

Main Question or Discussion Point

Hi

1) I have read in an article that the atoms in a lattice are at "half-filling". As I understand, this means that the chemical potential is zero. Why does "half-filling" mean since it equals that the chemical potential is zero?

2) Lets say that I place an impurity with potential U0 in my lattice. Does it make a difference whether U0 is positive or negative? What is the usual case?

Best regards and happy Easter,
Niles.
 

Answers and Replies

  • #2
415
0
1) Half filling means every site in the lattice has a single particle. Since each site can hold two particles, you are at helf filliing. The chemical potential being zero is a consequence of having a symmetric band structure and an on site energy of zero.

2) Yes it matters whether U0 is positive or negative. I think there is no usual case, it depends on what kind of model you want to study.
 
  • #3
1,868
0
Thanks. Regarding #2, if I set U0>0, then it "costs" more energy to be there, right?
 
  • #4
415
0
Right
 

Related Threads on Potential and impurities

Replies
3
Views
1K
  • Last Post
Replies
1
Views
3K
Replies
4
Views
819
  • Last Post
Replies
4
Views
2K
Replies
3
Views
898
  • Last Post
Replies
1
Views
2K
Replies
0
Views
767
  • Last Post
Replies
1
Views
2K
Replies
1
Views
3K
  • Last Post
Replies
6
Views
1K
Top