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arXiv · 1908.10361

Two-particle Correlation Functions in Cluster Perturbation Theory: Hubbard Spin Susceptibilities

P. T. Raum·G. Alvarez·Thomas Maier·V. W. Scarola
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Abstract

Cluster Perturbation Theory (CPT) is a computationally economic method commonly used to estimate the momentum and energy resolved single-particle Green's function. It has been used extensively in direct comparisons with experiments that effectively measure the single-particle Green's function, e.g., angle-resolved photoemission spectroscopy. However, many experimental observables are given by two-particle correlation functions. CPT can be extended to compute two-particle correlation functions by approximately solving the Bethe-Salpeter equation. We implement this method and focus on the transverse spin-susceptibility, measurable via inelastic neutron scattering or with optical probes of atomic gases in optical lattices. We benchmark the method with the one-dimensional Fermi-Hubbard model at half filling by comparing with known results.

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P. T. Raum, G. Alvarez, Thomas Maier, V. W. Scarola. 2019-08-27. Two-particle Correlation Functions in Cluster Perturbation Theory: Hubbard Spin Susceptibilities. https://doi.org/10.1103/physrevb.101.075122

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