Post-experiment coincidence detection techniques for direct detection of two-body correlations

Abstract It is one challenge to develop experimental techniques for direct detection of the many-body correlations of strongly correlated electrons, which exhibit a variety of unsolved mysteries. In this article, we present a post-experiment coincidence counting method and propose two post-experiment coincidence detection techniques, post-experiment coincidence angle-resolved photoemission spectroscopy and post-experiment coincidence inelastic neutron scattering. By coincidence detection of two photoelectric processes or two neutron-scattering processes, the post-experiment coincidence detection techniques can detect directly the two-body correlations of strongly correlated electrons in particle-particle channel or two-spin channel. The post-experiment coincidence detection techniques can be implemented upon the pulse -resolved angle-resolved photoemission spectroscopy or inelastic neutron scattering experimental apparatus with pulse photon or neutron source. When implemented experimentally, they will be powerful techniques to study the highly esoteric high-temperature superconductivity and the highly coveted quantum spin liquids.