Confinement induced molecules in a 1D Fermi gas

TL;DR

This paper reports the experimental observation of confinement-induced molecules in a one-dimensional Fermi gas, demonstrating bound states that exist regardless of scattering length sign and matching theoretical predictions.

Contribution

It provides the first direct measurement of confinement-induced molecules in a 1D Fermi gas and confirms theoretical models with experimental data.

Findings

Observation of two-particle bound states in 1D confinement

Binding energy measurements agree with theoretical predictions

Bound states exist regardless of scattering length sign

Abstract

We have observed two-particle bound states of atoms confined in a one-dimensional matter wave guide. These bound states exist irrespective of the sign of the scattering length, contrary to the situation in free space. Using radio-frequency spectroscopy we have measured the binding energy of these dimers as a function of the scattering length and confinement and find good agreement with theory. The strongly interacting one-dimensional Fermi gas which we create in an optical lattice represents a realization of a tunable Luttinger liquid.