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Generalized Hartree Fock Theory for Dispersion Relations of Interacting Fermionic Lattice Systems

Quantum Physics 2013-11-20 v1 Strongly Correlated Electrons

Abstract

We study the variational solution of generic interacting fermionic lattice systems using fermionic Gaussian states and show that the process of "gaussification", leading to a nonlinear closed equation of motion for the covariance matrix, is locally optimal in time by relating it to the time-dependent variational principle. By linearising our nonlinear equation of motion around the ground-state fixed point we describe a method to study low-lying excited states leading to a variational method to determine the dispersion relations of generic interacting fermionic lattice systems. This procedure is applied to study the attractive and repulsive Hubbard model on a two-dimensional lattice.

Keywords

Cite

@article{arxiv.1205.5113,
  title  = {Generalized Hartree Fock Theory for Dispersion Relations of Interacting Fermionic Lattice Systems},
  author = {Christina V. Kraus and Tobias J. Osborne},
  journal= {arXiv preprint arXiv:1205.5113},
  year   = {2013}
}