Ultracold fermionic gases

K. Dieckmann, C.A. Stan, S. Gupta, Z. Hadzibabic, C. Schunck, W. Ketterle Decay of ultracold fermionic lithium gas near a Feshbach resonance. Phys. Rev. Lett. 89, 203 201 (2002)... 

Fig. 8.2 A quantum degenerate gas of ultracold atoms reaches degeneracy when the matter waves of neighboring atoms overlap (a) at absolute zero, gaseous bosonic atoms all end up in the lowest energy state (b) fermions, in contrast, fill the states with one atom per state, and the energy of the highest filled state at T = 0 is the Fermi energy Ep ...

A Fermi-degenerate gas can coexist with a Bose-Einstein condensate. This was observed, for example, in experiments with an ultracold atomic mixture of Li atoms (bosons) and Li atoms (fermions) at a temperature of T = 0.28/l(K and Tf=0.2Tc, where Tp and Tc are the Fermi and the Bose-Einstein condensation critical temperature, respectively (Schreck et al. 2001). 

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