Comparison of strong-coupling theories for a two-dimensional Fermi gas

Understanding the formation of Cooper pairs and the resulting thermodynamic properties of low-dimensional Fermi gases is an important area of research, which may help build our understanding of other low-dimensional systems, such as high-temperature superconductors. In lower dimensions, quantum fluctuations are expected to play an increasingly important role, and the reliability of strong-coupling theories becomes questionable. Here, we present a comparison of recent thermodynamic measurements and theoretical predictions from different many-body T-matrix theories for a two-dimensional strongly interacting Fermi gas in the normal state. We find that the fully self-consistent T-matrix theory provides the best description of the experimental data over a wide range of temperatures and interatomic interactions.