Abstract
The zero-temperature pairing gap is a fundamental property of interacting Fermions, providing a crucial test of many-body theories in strong coupling. We analyze recent cold-atom experiments on imbalanced Fermi systems using Quantum Monte Carlo results for the superfluid and normal phases. Through this analysis we extract, for the first time, the experimental zero-temperature pairing gap in the fully paired superfluid state at unitarity where the two-body scattering length is infinite. We find that the zero-temperature pairing gap is greater than 0.4 times the Fermi energy , with a preferred value of () . The ratio of the pairing gap to the Fermi Energy is larger here than in any other Fermi system measured to date.
- Received 16 November 2007
DOI:https://doi.org/10.1103/PhysRevLett.100.150403
©2008 American Physical Society