  We report the experiment on probing the one-body spectral function in a
trapped non-interacting $^{40}$K Fermi gas by means of the momentum-resolved
Raman spectroscopy The experimental result is in good agreement with the
expected quadratic dispersion in the non-interacting regime. Through the
comparison with the radio-frequency spectrum, we found that the Raman spectrum
shows some new characteristics.

Quantum Gases