论文标题
玻色子交换式镶木求解器
Boson-Exchange Parquet Solver for dual fermions
论文作者
论文摘要
我们基于双顶点函数的部分琼脂化，在双屈服形式主义中介绍并实施了一个镶木近似，这大大降低了计算的计算成本。该方法依赖于将顶点完全分解为单个验证交换贡献和残留的四晶顶顶点，它们在物理上分别体现了长距离和短距离的空间相关性。在用残留顶点重新铸造镶木quet方程后，使用Eckhardt等人的截断统一方法来解决这些方程。 [物理。 Rev. b 101，155104（2020）]，它允许在不同制度中的形式数量迅速收敛。虽然我们对木板方程的数值处理只能仅限于几个Matsubara频率，但让人联想到Astretsov等。 [物理。 Rev. B 101，075109（2020）]，单粒光谱信息被完全保留。在对二维Hubbard模型的应用中，该方法在广泛的参数上定量地与图表的随机总和一致。
We present and implement a parquet approximation within the dual-fermion formalism based on a partial bosonization of the dual vertex function which substantially reduces the computational cost of the calculation. The method relies on splitting the vertex exactly into single-boson exchange contributions and a residual four-fermion vertex, which physically embody respectively long-range and short-range spatial correlations. After recasting the parquet equations in terms of the residual vertex, these are solved using the truncated unity method of Eckhardt et al. [Phys. Rev. B 101, 155104 (2020)], which allows for a rapid convergence with the number of form factors in different regimes. While our numerical treatment of the parquet equations can be restricted to only a few Matsubara frequencies, reminiscent of Astretsov et al. [Phys. Rev. B 101, 075109 (2020)], the one- and two-particle spectral information is fully retained. In applications to the two-dimensional Hubbard model the method agrees quantitatively with a stochastic summation of diagrams over a wide range of parameters.
