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Nov
22
revised What is a free fermion model?
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Nov
16
awarded  Editor
Nov
16
revised What is a free fermion model?
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Nov
10
comment What is a free fermion model?
@LuboŇ°Motl Also, if you were to expand your comment as an answer, I'd be happy to accept it.
Nov
9
comment What is a free fermion model?
@LuboŇ°Motl Thank you. So the example Hamiltonian is a free fermion model since in fermions, it only contains $\sum_l a_l^\dagger a_{l+1}$ and $\sum_l (-1)^l a_l^\dagger a_{l+1}$ type terms. By this reasoning, even a spin chain $H_2 = - \sum_l J_l (\sigma_l^x \sigma_{l+1}^x + \sigma_l^y \sigma_{l+1}^y)$ where $J_l$ is different for each $l$ is a free fermion model. Is that right?
Nov
8
comment What is a free fermion model?
@Qmechanic Thank you for replying. As far I can see, Icv's answer just mentions free fermion models but doesn't say what they actually are, which is what I'm asking.
Nov
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awarded  Student
Nov
8
asked What is a free fermion model?