Two-particle correlation functions in cluster perturbation theory: Hubbard spin susceptibilities

Journal Article · 18 February 2020 · Physical Review B

DOI: https://doi.org/10.1103/PhysRevB.101.075122 · OSTI ID:1608218

Raum, P. ^[1]; Alvarez, Gonzalo  ^[2]; Maier, Thomas  ^[2]; Scarola, Vito  ^[1]

---

1. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States)
2. Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

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. Finally, we benchmark the method with the one-dimensional Fermi-Hubbard model by comparing with known results.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR); USDOE Office of Science (SC), Basic Energy Sciences (BES); US Air Force Office of Scientific Research (AFOSR); US Army Research Office (ARO)
• Grant/Contract Number: AC05-00OR22725; FA9550-18-1-0505; W911NF-16-1-0182
• OSTI ID: 1608218
• Alternate ID(s): OSTI ID: 1600063
• Journal Information: Physical Review B, Vol. 101, Issue 7; ISSN 2469-9950
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English