Tagged Questions
4
votes
1answer
191 views
How to evaluate spin operators in second quantization for spin symmetry-broken Slater determinants?
Suppose we have the following Slater determinant:
\begin{equation}
| \Psi \rangle = \prod \limits_{i,i'} a^+_{i\alpha} a^+_{i'\beta} | \rangle
\end{equation}
where $a^+_{i\alpha}$ creates an electron ...
4
votes
1answer
107 views
Why is the Wick contraction in HFB or BCS equal to a single-particle density?
I'm trying to understand how in Hartree-Fock-Bogoliubov
(HFB) or BCS theory we can write a product of creation/annihilation operators as single-particle densities under the guise of "Wick's theorem".
...
5
votes
1answer
141 views
Is it possible to make statements about bosonic/fermionic systems by taking the limit $\theta\to \pi$ or $\theta\to 0$, of an anyonic system?
One might naïvely write the (anti-)commutation relations for bosonic/fermionic ladder operators as limits
$$
\delta_{k,\ell} = \bigl[ \hat{b}_{k}, \hat{b}_{\ell}^\dagger \bigr]
= ...
7
votes
1answer
3k views
Kubo Formula for Quantum Hall Effect
I'm trying to understand the Kubo Formula for the electrical conductivity in the context of the Quantum Hall Effect.
My problem is that several papers, for instance the famous TKNN (1982) paper, or ...
