Towards higher Tc in bilayer optical lattice with a potential difference

There have been a lot of efforts on simulating the Fermi Hubbard model in the cold atom optical lattice system. One particular goal is to realize a superconducting phase similar to the high Tc superconductor in cuprates. However, the accessible temperature now is still one order larger than the expected critical temperature. Here we propose to study a bilayer optical lattice system with a potential difference, which may host a stronger superconductor with much larger Tc. Through controlling the potential difference, we can make one layer at density n=1 and the other layer at density n=1-x. Then the system can simulates a Kondo model with a usual t-J model in one layer coupled to spin moments in the other layer. The spin flcutuations in the other layer can enhance the pairing stregnth of the t-J layer. We will show numerical and analytical evidences for enhanced spin gap by several times. The system can also be used to study Kondo transition observed in heavy Fermion systems.