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Equation of motion approach to the Hubbard model in infinite dimensions

Claudius Gros
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Abstract

We consider the Hubbard model on the infinite-dimensional Bethe lattice and construct a systematic series of self-consistent approximations to the one-particle Green's function, $G^{(n)}(ω),\ n=2,3,\dots\ $ . The first $n-1$ equations of motion are exactly fullfilled by $G^{(n)}(ω)$ and the $n$'th equation of motion is decoupled following a simple set of decoupling rules. $G^{(2)}(ω)$ corresponds to the Hubbard-III approximation. We present analytic and numerical results for the Mott-Hubbard transition at half filling for $n=2,3,4$.

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Claudius Gros. 1994-03-08. Equation of motion approach to the Hubbard model in infinite dimensions. https://doi.org/10.1103/physrevb.50.7295

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