2014/10/22 by Zhichao Zhou, Zi Cai, Congjun Wu +1 · 1 citation
Physics and Astronomy · #cond-mat.quant-gas
paper · pdf · doi:10.1103/physrevb.90.235139
published as Phys. Rev. B 90, 235139 (2014) · 10 pages, 6 figures
arxiv created 2014/10/22 · arxiv updated 2015/02/02
We have systematically studied the thermodynamic properties of a two-dimensional half-filled SU(2N) Hubbard model on a square lattice by using the determinant quantum Monte Carlo method. The entropy-temperature relation, the isoentropy curve, and the probability distribution of the onsite occupation number are calculated in both SU(4) and SU(6) cases, which exhibit prominent features of the Pomeranchuk effect. We analyze these thermodynamic behaviors based on charge and spin energy scales. In the charge channel, the interaction strength that marks the crossover from the weak to strong interaction regimes increases with the number of fermion components. In the spin channel, increasing the number of fermion components enhances quantum spin fluctuations, which is shown in the simulations of uniform spin susceptibilities and antiferromagnetic structure factors.