Unconventional pairing in few-fermion systems tuned by external confinement

Abstract

We study the ground-state properties of a two-component one-dimensional system of a few ultra-cold fermions with attractive interactions. We show that, by ramping up an external potential barrier felt by one of the components, it is possible to induce regions of exotic superfluid phases, characterized by a tunable finite net momentum of the Cooper pair, without changing the overall spin populations. We show that these phases, which are the few-body analogs of the celebrated Fulde-Ferrell-Larkin-Ovchinnikov state, can be distinguished by analyzing a specific two-particle correlation encoded in the noise correlation function. Our theoretical results can be addressed in current experiments with cold atoms confined in spin-selective optical traps.

11 pages, 7 figures

References in corpus (21)

• Many-Body Physics with Ultracold Gases
• Theory of ultracold Fermi gases
• Single-Spin Addressing in an Atomic Mott Insulator
• Phase diagram of a strongly interacting polarized Fermi gas in one dimension
• Ultra-cold Polarized Fermi Gases
• Pairing states of a polarized Fermi gas trapped in a one-dimensional optical lattice
• Sublattice addressing and spin-dependent motion of atoms in a double-well lattice
• Density-Matrix Renormalization Group Study of Trapped Imbalanced Fermi Condensates
• Exact quantum Monte Carlo study of one dimensional trapped fermions with attractive contact interactions
• Exact Numerical Study of Pair Formation with Imbalanced Fermion Populations
• The FFLO state in the one-dimensional attractive Hubbard model and its fingerprint in the spatial noise correlations
• Manipulation of Single Neutral Atoms in Optical Lattices
• Long-time behavior of the momentum distribution during the sudden expansion of a spin-imbalanced Fermi gas in one dimension
• Spectral signatures of the Fulde-Ferrell-Larkin-Ovchinnikov order parameter in one-dimensional optical lattices
• Pairing in a system of a few attractive fermions in a harmonic trap
• Probing the FFLO phase by double occupancy modulation spectroscopy
• Signature of the FFLO phase in the collective modes of a trapped ultracold Fermi gas
• Expansion of 1D polarized superfluids: The FFLO state reveals itself
• Pairing of few Fermi atoms in one dimension
• Interaction quantum quenches in the one-dimensional Fermi-Hubbard model with spin imbalance
• Few-body perspective on fermionic pairing in one spatial dimension