Spatially varying interactions induced in atomic gases by optical Feshbach resonance

Optical Feshbach resonance is capable of inducing spatially varying interactions in ultra-cold atoms. Its applications to pancake-shaped clouds of bosons and fermions enable one to study several fresh phenomena. We examine possibilities of inducing counter-intuitive structures such as creating a superfluid enclave inside a Mott insulator for bosons and a normal-gas core enclosed by a superfluid shell for fermions. We discuss feasible experimental setups and signatures of those interesting structures, which can be very different from common structures observed in experiments so far. While a superfluid enclave in a Mott insulator can be useful for constructing atomic devices for atomtronics, superconducting islands observed in scanning-tunneling microscopy of heavily underdoped high-temperature superconductors may be studied with cold Fermi gases with spatially varying attractions.