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

• DOI: 10.1126/science.aan5950
• Publication Date: 2017-12-21T19:09:45Z
• Authors: Puneet A. Murthy; Mathias Neidig; Ralf Klemt; Luca Bayha; Igor Boettcher; Tilman Enss; Marvin Holten; Gerhard Zürn; Philipp M. Preiss; Selim Jochim
• Keywords: Superconductivity (cond-mat.supr-con); Condensed Matter - Strongly Correlated Electrons; Strongly Correlated Electrons (cond-mat.str-el); Quantum Gases (cond-mat.quant-gas); Condensed Matter - Superconductivity; 0103 physical sciences; FOS: Physical sciences; Condensed Matter - Quantum Gases; 01 natural sciences

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 energies spanning wide range and interaction strengths. In strongly interacting regime where scattering length between fermions is on same order as inter-particle spacing, energy normal phase significantly exceeds intrinsic two-body binding system shows clear dependence local density. This implies that this driven by correlations, rather than physics. find effect persist close Fermi which demonstrates correlations systems are remarkably robust against thermal fluctuations.