Polarons in the radio-frequency spectrum of a quasi-two-dimensional   Fermi gas
  We measure radio-frequency spectra for a two-component mixture of a $^6$Li atomic Fermi gas in the quasi-two-dimensional regime. Near the Feshbach resonance, where the transverse Fermi energy is large compared to the confinement-induced dimer binding energies for the initial and final states, we find that the observed resonances do not correspond to transitions between confinement-induced dimers. The spectrum appears to be well-described by transitions between noninteracting polaron states in two dimensions. 
Y. Zhang, W. Ong, I. Arakelyan, and J. E. Thomas
cond-mat.quant-gas