Atom Pairing in Optical Superlattices*

We study the pairing of fermions in a one-dimensional optical superlattice of double-well potentials with tunable asymmetry. Radio frequency spectroscopy reveals the coexistence of two types of atom pairs with different symmetries for their center of mass wave functions. Our measurements are in excellent quantitative agreement with a multi-band model of the spectra, comprising 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.