Stability of the Repulsive Fermi Gas with Contact Interactions

Observation of Anomalous Decay of a Polarized Three-Component Fermi Gas

“…Furthermore, the corresponding binding energies of the |12 and |23 dimers are such that all recombination products escape from the box (see section VII). Thus, a mixture of spins |i − |j would decay following a recombination law ṅj = −L ij 3 (2n 2 j n i + n 2 i n j )/3 [32,39]. We note that the two-component recombination rates agree with the universal prediction of [39] (solid lines of Fig.…”

“…S2B). At higher magnetic fields, the formation of |12 and |23 dimers does not directly lead to losses, as their binding energies are less than 6U box [32].…”

“…The intermediate range B ≈ 720 − 810 G is more complicated, and γ deviates from 3. In that region, the scattering lengths a 12 and a 23 , respectively between states |1 − |2 and |2 − |3 , are large and positive, so that the products of three-body recombination can remain trapped [32,39]. This allows for subsequent inelastic atom-dimer collisions (involving three distinguishable atoms), an effectively two-body loss process [40][41][42].…”

“…Such spatially homogeneous gases generally obey simpler dynamics than their inhomogeneous counterparts (see e.g. [10,[31][32][33]). This has enabled us to observe a surprising violation of the generic expectation that loss rates among spin components should be equal in a three-body process involving all three components.…”

Three-body contact for fermions. I. General relations

“…where the constant M was given in (24). This result immediately follows from (23) and from the relation…”