Atom Pairing in Optical Superlattices

TL;DR

This paper investigates fermion pairing in a tunable 1D optical superlattice, revealing two pairing symmetries through radio-frequency spectroscopy and matching a detailed theoretical model, advancing understanding of elementary pairing states.

Contribution

It extends the Green's function method to a bichromatic 1D lattice with radial confinement, providing a comprehensive theoretical framework for pairing in superlattices.

Findings

Identification of two atom pair symmetries in the superlattice

Quantitative agreement between experimental spectra and the extended model

Prediction of hundreds of discrete transition spectra

Abstract

We study the pairing of fermions in a one-dimensional lattice of tunable double-well potentials using radio-frequency spectroscopy. The spectra reveal the coexistence of two types of atom pairs with different symmetries. Our measurements are in excellent quantitative agreement with a theoretical model, obtained by extending the Green's function method of Orso et al., [Phys. Rev. Lett. 95, 060402 (2005)], to a bichromatic 1D lattice with finite harmonic radial confinement. The predicted spectra comprise hundreds of discrete transitions, with symmetry-dependent initial state populations and transition strengths. Our work provides an understanding of the elementary pairing states in a superlattice, paving the way for new studies of strongly interacting many-body systems.