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Construction of size-consistent effective Hamiltonians for systems with arbitrary Hilbert space

Arnd Huebsch·Matthias Vojta·Klaus W. Becker
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Abstract

Effective Hamiltonians are usually constructed by using canonical transformations or projection techniques. In contrast to this, we present a method for systems with arbitrary Hilbert space based on the introduction of cumulants. Cumulants guarantee size consistency, a property that is not always evident in other treatments. As a nontrivial example of use the derived method is applied to the strong-coupling limit of the half-filled Hubbard model on a general lattice in arbitrary spatial dimension for which the fourth-order expansion in t/U of the effective Hamiltonian is derived.

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Arnd Huebsch, Matthias Vojta, Klaus W. Becker. 1999-09-22. Construction of size-consistent effective Hamiltonians for systems with arbitrary Hilbert space. https://doi.org/10.1088/0953-8984%2F11%2F43%2F316

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