All Questions
1
question
7
votes
1
answer
4k
views
Ground state degeneracy: Spin vs Fermionic language
Let us first consider the Hamiltonian of well-known 1D periodic Ising model as
$$
H = -\frac{1}{2} \sum_{j=1}^N \sigma^x_j \sigma^x_{j+1} + \frac{h}{2}\sum_{j=1}^N \sigma^z_j.
$$
Now, in the ...
- 173