d-Wave Superfluidity
A plaquette (left) is the minimum system that exhibits d-wave symmetry. When loaded with four fermions, the ground state is d-wave symmetric; when loaded with two fermions, the ground state exhibits S-wave symmetry. Consequently the two states have a nonzero matrix element with the d-wave pair-creation operator. We propose to load an array of plaquettes with cold atoms to engineer d-wave superfluidity.
After many years of work, we still do not understand the basic mechanism responsible for high-temperature superconductivity. Theorists believe that the Hubbard Hamiltonian is the minimal model capable of explaining it. Ultracold Fermionic atoms trapped in optical lattices provide a clean implementation of the Hubbard Hamiltonian and can yield insight on its phase diagram. We have proposed a new approach for controllable preparation and detection of d-wave superfluidity in these systems. Our approach employs an array of plaquettes created via 2D optical superlattices.
