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arXiv · 1205.5113

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

Christina V. Kraus·Tobias J. Osborne
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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.

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Christina V. Kraus, Tobias J. Osborne. 2012-05-23. Generalized Hartree Fock Theory for Dispersion Relations of Interacting Fermionic Lattice Systems. https://doi.org/10.1103/physrevb.88.195126

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