Testing one-body density functionals on a solvable model

TL;DR

This paper evaluates various one-body density matrix functionals using a solvable model and phase-space formalism to assess their accuracy and applicability in quantum systems.

Contribution

It introduces a comprehensive testing framework for density matrix functionals on a solvable model using phase-space methods, providing insights into their performance.

Findings

Certain functionals accurately reproduce the model's properties

Some functionals show limitations in specific regimes

Phase-space formalism aids in detailed analysis

Abstract

There are several physically motivated density matrix functionals in the literature, built from the knowledge of the natural orbitals and the occupation numbers of the one-body reduced density matrix. With the help of the equivalent phase-space formalism, we thoroughly test some of the most popular of those functionals on a completely solvable model.