Fermions in 3D optical lattices: cooling protocol to obtain antiferromagnetism.
Fermions in 3D optical lattices: cooling protocol to obtain antiferromagnetism.
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DOI：
10.1103/physrevlett.107.086401
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发表时间：
2011-06
影响因子：
8.6
通讯作者：
T. Paiva;Y. Loh;M. Randeria;R. Scalettar;N. Trivedi
中科院分区：
文献类型：
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作者：
T. Paiva;Y. Loh;M. Randeria;R. Scalettar;N. Trivedi
在光学晶格中实现反铁磁和超流相的一个主要挑战是冷却费米子的能力。我们确定的状态方程的3D排斥费米-哈伯德模型作为一个函数的化学势，温度和排斥使用无偏的行列式量子蒙特卡罗方法，然后我们使用局域密度近似模型的谐波陷阱。我们发现，增加排斥导致冷却，但只有在一个陷阱，由于熵的重新分配从中心到金属翅膀。因此，即使每个粒子的平均熵大于均匀系统中反铁磁性所需的熵，陷阱也能形成反铁磁性的莫特相。
A major challenge in realizing antiferromagnetic and superfluid phases in optical lattices is the ability to cool fermions. We determine the equation of state for the 3D repulsive Fermi-Hubbard model as a function of the chemical potential, temperature, and repulsion using unbiased determinantal quantum Monte Carlo methods, and we then use the local density approximation to model a harmonic trap. We show that increasing repulsion leads to cooling but only in a trap, due to the redistribution of entropy from the center to the metallic wings. Thus, even when the average entropy per particle is larger than that required for antiferromagnetism in the homogeneous system, the trap enables the formation of an antiferromagnetic Mott phase.