  We determine the three-body bound states of an atom in a Fermi mixture.
Compared to the Efimov spectrum of three atoms in vacuum, we show that the
Fermi seas deform the Efimov spectrum systematically. We demonstrate that this
effect is more pronounced near unitarity, for which we give an analytical
estimate. We show that in the presence of Fermi seas, the three-body bound
states obey a generalized discrete scaling law. For an experimental
confirmation of our prediction, we propose three signatures of three-body bound
states of an ultracold Fermi mixture of Yb isotopes, and provide an estimate
for the onset of the bound state and the binding energy.
