Controlled Preparation and Detection of d-Wave Superfluidity in Two-Dimensional Optical Superlattices

Abstract

(d)-wave Cooper pairs are believed to be the key for understanding the phenomenon of high-temperature superconductivity in cuprates. These superconductors are an example of the emergence of strong pairing in systems with purely repulsive interactions, similar to superfluid helium 3 and the newly discovered iron oxypnictides. Despite intense studies, there is currently no consensus as to what causes the formation of (d)-wave Cooper pairs in these materials. Here we propose a novel experimental scheme in which recently demonstrated methods for realizing optical lattices and superlattices are combined to create and to detect, in a controlled way, ultracold-atom (d)-wave Cooper pairs. Our scheme starts from arrays of isolated plaquettes which incorporate the required (d)-wave correlations on a short length scale. By tuning the parameters of the potentials, these plaquettes can be coupled to achieve long-range (d)-wave superfluid correlations, finally arriving at the generic Hubbard model.