Cluster-size dependence in cellular dynamical mean-field theory
Cluster-size dependence in cellular dynamical mean-field theory
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DOI：
10.1103/physrevb.85.035102
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发表时间：
2011-12
影响因子：
3.7
通讯作者：
S. Sakai;G. Sangiovanni;M. Civelli;Y. Motome;K. Held;M. Imada
中科院分区：
文献类型：
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作者：
S. Sakai;G. Sangiovanni;M. Civelli;Y. Motome;K. Held;M. Imada
我们研究团簇大小的依赖性的细胞动力学平均场理论（CDMFT）应用于二维哈伯德模型。采用连续时间量子Monte Carlo方法作为有效团簇模型的求解器，我们在低温下获得了4-，8-，12-和16-位团簇的CDMFT解。比较各种周期化方案，这是用来构建的无限晶格数量从集群的结果，我们发现，累积周期化产生最快的收敛空穴掺杂莫特绝缘体的最严重的尺寸依赖性是预期的。我们还发现，在（0，0）和（pi/2，pi/2）附近的收敛速度要比在（pi，0）和（pi，pi）附近的收敛速度快得多。的累积周期化的自能似乎是接近其热力学极限已经为一个16网站集群的参数范围内的研究。4位团簇的结果与16位团簇的结果非常吻合，表明以前基于4位团簇的研究抓住了掺杂Mott绝缘体的物理本质。
We examine the cluster-size dependence of the cellular dynamical mean-field theory (CDMFT) applied to the two-dimensional Hubbard model. Employing the continuous-time quantum Monte Carlo method as the solver for the effective cluster model, we obtain CDMFT solutions for 4-, 8-, 12-, and 16-site clusters at a low temperature. Comparing various periodization schemes, which are used to construct the infinite-lattice quantities from the cluster results, we find that the cumulant periodization yields the fastest convergence for the hole-doped Mott insulator where the most severe size dependence is expected. We also find that the convergence is much faster around (0,0) and (pi/2,pi/2) than around (pi,0) and (pi,pi). The cumulant-periodized self-energy seems to be close to its thermodynamic limit already for a 16-site cluster in the range of parameters studied. The 4-site results remarkably agree well with the 16-site results, indicating that the previous studies based on the 4-site cluster capture the essence of the physics of doped Mott insulators.