Pomeranchuk cooling of the SU($2N$) ultra-cold fermions in optical   lattices
  We investigate the thermodynamic properties of a half-filled SU(2N) Fermi-Hubbard model in the two-dimensional square lattice using the determinantal quantum Monte Carlo simulation, which is free of the fermion "sign problem". The large number of hyperfine-spin components enhances spin fluctuations, which facilitates the Pomeranchuk cooling to temperatures comparable to the superexchange energy scale at the case of SU$(6)$. Various quantities including entropy, charge fluctuation, and spin correlations have been calculated. 
Zi Cai, Hsiang-hsuan Hung, Lei Wang, Dong Zheng, Congjun Wu
cond-mat.quant-gas