Cluster formation in two-component Fermi gases

Abstract

Two-component fermions are known to behave like a gas of molecules in the limit of Bose-Einstein condensation of diatomic pairs tightly bound with zero-range interactions. We discover that the formation of cluster states occurs when the effective range of two-body interaction exceeds roughly $0.46$ times the scattering length, regardless of the details of the short-range interaction. Using explicitly correlated Gaussian basis set expansion approach, we calculate the binding energy of cluster states in trapped few-body systems and show the difference of structural properties between cluster states and gas-like states. We identify the condition for cluster formation and discuss potential observation of cluster states in experiments.

5+3 pages, 4+4 figures, accepted for publication in PRL

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Cited by in corpus (4)

• Role of the effective range in the density-induced BEC-BCS crossover
• Theory of strongly paired fermions with arbitrary short-range interactions
• Polariton-polariton interaction beyond the Born approximation: A toy model study
• A model study on superfluidity of a unitary Fermi gas of atoms interacting with a finite-ranged potential