Fermion Mediated Interactions Between Ultracold Bosons
Ian B. Spielman, Subhadeep De
We describe a new method for creating spin-dependent long-range interactions between atomic ultra-cold neutral bosons in an optical lattice. In this proposal, the bosonic system is immersed in a spin polarized degenerate Fermi gas. We first show that the bosons acquire a long-range interaction analogous to RKKY interaction in solids. The resulting fermion mediated Bose-Bose interaction, which can depend on the bosons' spin state, is tunable using inter-species Feshbach resonance. When the bosons are subject to a suitable optical lattice, 3-body loss process are greatly suppressed. We conclude by showing that these interactions can lead to a supersolid phase for single spin Bose system, and also to a fully tunable transverse field Ising model for a two component Bose system.