Universal thermodynamics of an SU(N) Fermi-Hubbard model
Universal thermodynamics of an SU(N) Fermi-Hubbard model
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DOI：
10.1103/physreva.104.043316
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发表时间：
2021-08
影响因子：
2.9
通讯作者：
Eduardo Ibarra-Garc'ia-Padilla;S. Dasgupta;Hao-Tian Wei;S. Taie;Y. Takahashi;R. Scalettar;K. Hazzard
中科院分区：
文献类型：
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作者：
Eduardo Ibarra-Garc'ia-Padilla;S. Dasgupta;Hao-Tian Wei;S. Taie;Y. Takahashi;R. Scalettar;K. Hazzard
SU（2）对称费米-哈伯德模型（FHM）在强关联费米多体系统中起着重要作用。在每个站点一个粒子和强相互作用限制${U/t \gg 1}$，它有效地描述了海森堡哈密顿量。在这个极限下，扩大自旋并将典型的SU（2）对称性扩展到SU（$N$），已经被预测会给出基态物质的奇异相，并对$N$有复杂的依赖性。这就提出了一个问题，什么-如果有的话-是这些阶段的有限温度签名，特别是在目前的实验相关制度附近或以上的超交换能量。我们探讨这个问题的热力学观测值通过数值计算的热力学SU（$N$）FHM在二维正方形晶格密度附近的每个站点，使用行列式量子蒙特卡罗和数值连锁集群扩展。有趣的是，我们发现，对于温度以上的超交换能量，其中的相关长度是短的，能量，现场对的数量，和动能是N$的通用函数。虽然在该制度的物理研究是远远超出了可以捕获的低阶高温系列，我们表明，分析描述的缩放是可能的，只有一个和两个网站的计算。
The SU(2) symmetric Fermi-Hubbard model (FHM) plays an essential role in strongly correlated fermionic many-body systems. In the one particle per site and strongly interacting limit ${U/t \gg 1}$, it is effectively described by the Heisenberg Hamiltonian. In this limit, enlarging the spin and extending the typical SU(2) symmetry to SU($N$) has been predicted to give exotic phases of matter in the ground state, with a complicated dependence on $N$. This raises the question of what --- if any --- are the finite-temperature signatures of these phases, especially in the currently experimentally relevant regime near or above the superexchange energy. We explore this question for thermodynamic observables by numerically calculating the thermodynamics of the SU($N$) FHM in the two-dimensional square lattice near densities of one particle per site, using determinant Quantum Monte Carlo and Numerical Linked Cluster Expansion. Interestingly, we find that for temperatures above the superexchange energy, where the correlation length is short, the energy, number of on-site pairs, and kinetic energy are universal functions of $N$. Although the physics in the regime studied is well beyond what can be captured by low-order high-temperature series, we show that an analytic description of the scaling is possible in terms of only one- and two-site calculations.