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An effective Hamiltonian for phase fluctuations on a lattice: an extended XY model

Superconductivity 2009-11-07 v1

Abstract

We derive an effective Hamiltonian for phase fluctuations in an s-wave superconductor starting from the attractive Hubbard model on a square lattice. In contrast to the common assumption, we find that the effective Hamiltonian is not the usual XY model but is of an extended XY type. This extended feature is robust and leads to essential corrections in understanding phase fluctuations on a lattice. The effective coupling in the Hamiltonian varies significantly with temperature.

Keywords

Cite

@article{arxiv.cond-mat/0111122,
  title  = {An effective Hamiltonian for phase fluctuations on a lattice: an extended XY model},
  author = {Wonkee Kim and J. P. Carbotte},
  journal= {arXiv preprint arXiv:cond-mat/0111122},
  year   = {2009}
}

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