Cooling schemes for ultracold gases in bilayer optical lattices

Recent observation of long-range magnetic ordering in an optical lattice system loaded with two-component Fermi gases [1] has highly motivated further technological development of the analog quantum simulator of the Hubbard model. Currently, the most severe bottleneck for the Hubbard quantum simulation is to reduce the temperature of the systems to be much lower than the spin-exchange interaction J. For instance, the critical temperature of the d-wave superconducting phases is estimated to be on the order of 0.1J/k_B with some approximate theory. Since the lowest temperature achieved in ultracold-atom quantum simulators is 0.45J/k_B [1], one needs to develop techniques for further cooling. In this talk, I will discuss a cooling scheme using layered optical lattices [2,3] and show that our proposed scheme can cool the system down to roughly half of the initial temperature.

[1] A. Mazurenko et al., Nature 545, 462 (2017).
[2] A. Kantian et al., arXiv:1609.03579 [cond-mat.quant-gas].
[3] S. Goto and I. Danshita, arXiv:1710.00521 [cond-mat.quant-gas].