Signatures of unconventional pairing in spin-imbalanced one-dimensional few-fermion systems

A system of a few attractively interacting fermionic Li-6 atoms in one-dimensional harmonic confinement is investigated. Nontrivial interparticle correlations induced by interactions in a particle-imbalanced system are studied in the framework of the noise correlation. In this way, it is shown that evident signatures of strongly correlated fermionic pairs in the Fulde-Ferrell-Larkin-Ovchinnikov state are present in the system and they can be detected by measurements directly accessible within state-of-the-art techniques. The results convincingly show that the exotic pairing mechanism is a very universal phenomenon and can be captured in systems being essentially nonuniform and far from the many-body limit.