# High temperature pairing in a strongly interacting two-dimensional Fermi gas

## TL;DR

This study demonstrates that in a strongly interacting two-dimensional ultracold Fermi gas, many-body pairing persists at temperatures near the Fermi temperature, driven by correlations beyond simple two-body physics.

## Contribution

The paper provides experimental evidence of many-body pairing above the superfluid transition temperature in a 2D Fermi gas, highlighting the role of correlations in strongly interacting regimes.

## Key findings

- Pairing energy exceeds two-body binding energy in the normal phase.
- Pairing correlations persist close to the Fermi temperature.
- Pairing driven by many-body effects, not just two-body physics.

## Abstract

We observe many-body pairing in a two-dimensional gas of ultracold fermionic atoms at temperatures far above the critical temperature for superfluidity. For this, we use spatially resolved radio-frequency spectroscopy to measure pairing energies spanning a wide range of temperatures and interaction strengths. In the strongly interacting regime where the scattering length between fermions is on the same order as the inter-particle spacing, the pairing energy in the normal phase significantly exceeds the intrinsic two-body binding energy of the system and shows a clear dependence on local density. This implies that pairing in this regime is driven by many-body correlations, rather than two-body physics. We find this effect to persist at temperatures close to the Fermi temperature which demonstrates that pairing correlations in strongly interacting two-dimensional fermionic systems are remarkably robust against thermal fluctuations.