Spatially resolved RF spectroscopy of a strongly interacting trapped Fermi gas

RF spectroscopy has been used to study unitary limited interactions and pairing in a strongly interacting Fermi mixture. However, most of the spectroscopy experiments have been performed with inhomogeneous samples confined in trapping potentials, eventually limited by the density broadening effects. We developed spatially resolved RF spectroscopy based on the \textit{in situ} imaging of the trapped samples. We obtained a density-broadening-free RF spectrum and clearly identified a gap in the RF spectrum of strongly interacting Fermi mixtures. In this talk, we will present a measurement of the paring gap energy of a Fermi mixuture at the unitarity limit.