Details

Autor(en) / Beteiligte

• Whitehead, T. M.
• Conduit, G. J.

Titel

Multiparticle instability in a spin-imbalanced Fermi gas

Ist Teil von

• Physical review. B, 2018-01, Vol.97 (1), Article 014502

Ort / Verlag

College Park: American Physical Society

Erscheinungsjahr

2018

Link zum Volltext

Quelle

American Physical Society

Beschreibungen/Notizen

• Weak attractive interactions in a spin-imbalanced Fermi gas induce a multiparticle instability, binding multiple fermions together. The maximum binding energy per particle is achieved when the ratio of the number of up- and down-spin particles in the instability is equal to the ratio of the up- and down-spin densities of states in momentum at the Fermi surfaces, to utilize the variational freedom of all available momentum states. We derive this result using an analytical approach, and verify it using exact diagonalization. The multiparticle instability extends the Cooper pairing instability of balanced Fermi gases to the imbalanced case, and could form the basis of a many-body state, analogously to the construction of the Bardeen-Cooper-Schrieffer theory of superconductivity out of Cooper pairs.