Interaction-expansion inchworm Monte Carlo solver for lattice and impurity models
Interaction-expansion inchworm Monte Carlo solver for lattice and impurity models
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DOI：
10.1103/physrevb.105.165133
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发表时间：
2022-01
影响因子：
3.7
通讯作者：
Jia Li;Yang Yu;E. Gull;G. Cohen
中科院分区：
文献类型：
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作者：
Jia Li;Yang Yu;E. Gull;G. Cohen
具有一般相互作用和杂交项的多轨道量子杂质模型出现在广泛的应用中，包括嵌入、量子传输和纳米科学。然而，大多数量子杂质求解器仅限于少数杂质轨道、离散浴、对角线杂化或密度-密度相互作用。在这里，我们将尺蠖量子蒙特卡罗方法推广到相互作用展开，并探索其在杂质和晶格模型研究中遇到的典型单轨道和多轨道问题的应用。在交互扩展方面，我们的实现通常优于裸线和粗线量子蒙特卡罗算法。到目前为止，对于这里研究的系统，它仍然不如更专业的杂交扩展和辅助场算法。收敛到非物理不动点的问题阻碍了所谓的粗线方法，但在尺蠖蒙特卡罗中没有遇到这种问题。
Multi-orbital quantum impurity models with general interaction and hybridization terms appear in a wide range of applications including embedding, quantum transport, and nanoscience. However, most quantum impurity solvers are restricted to a few impurity orbitals, discretized baths, diagonal hybridizations, or density-density interactions. Here, we generalize the inchworm quantum Monte Carlo method to the interaction expansion and explore its application to typical single- and multi-orbital problems encountered in investigations of impurity and lattice models. Our implementation generically outperforms bare and bold-line quantum Monte Carlo algorithms in the interaction expansion. So far, for the systems studied here, it remains inferior to the more specialized hybridization expansion and auxiliary field algorithms. The problem of convergence to unphysical fixed points, which hampers so-called bold-line methods, is not encountered in inchworm Monte Carlo.