All Questions
3
questions
5
votes
1
answer
924
views
Why does an energy band crossing the Fermi energy mean the gap closes?
This online course on topology in condensed matter states the following:
We say that two gapped quantum systems are topologically equivalent if their Hamiltonians can be continuously deformed into ...
- 3,986
1
vote
0
answers
60
views
Why are degenerate ground states interesting?
Studying the Su-Schrieffer-Heeger chain I have learned that the model has two different phases, one which is called topological and the other one trivial. In the notes it says that these phases are ...
- 1,772
4
votes
2
answers
1k
views
Topological invariant for interacting systems using single particle green functions?
Why Single particle green's function is (preferred) used to find topological for interacting systems?
$N_1 =\frac{\epsilon_{ijk}}{24 \Pi ^2} \int dw d^3k G \partial_i G^{-1}G\partial_jG^{-1}G\...
- 331