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arXiv 2602.22113cond-mat.str-elquant-ph
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降低二维费米子张量网络的温度

Lowering the temperature of two-dimensional fermionic tensor networks with cluster expansions

Ghent University(根特大学);Center for Molecular Modeling, Ghent University(根特大学分子建模中心)

Sander De Meyer, Atsushi Ueda, Yuchi He, Nick Bultinck, Jutho Haegeman

AI总结:

本文提出利用聚类展开方法构建二维费米子系统的PEPO近似,用于研究有限温度下的相变行为。

摘要:

将时间演化算子表示为张量网络是研究有限温度或非平衡量子晶格系统算法中的关键成分。对于由严格短程相互作用组成的哈密顿量, Suzuki-Trotter 分解是获得此类表示的主要技术。在[B. Vanhecke, L. Vanderstraeten和F. Verstraete, Physical Review A, L020402 (2021)]中,提出了一种替代策略,即聚类展开。该方法自然地保持内部和晶格对称性,并且可以更方便地扩展到更高阶的表示或更长程的相互作用。我们扩展了聚类展开到二维费米子系统,并利用它来构建投影纠缠对算子(PEPO)近似吉布斯态。我们还讨论并评估了不同截断方案在将多层PEPO相乘时的性能。将所得框架应用于具有吸引力相互作用的二维无质量费米子模型,我们清晰地确定了有限温度下的相界。

英文摘要:

Representing the time-evolution operator as a tensor network constitutes a key ingredient in several algorithms for studying quantum lattice systems at finite temperature or in a non-equilibrium setting. For a Hamiltonian composed of strictly short-ranged interactions, the Suzuki-Trotter decomposition is the main technique for obtaining such a representation. In [B.~Vanhecke, L.~Vanderstraeten and F.~Verstraete, Physical Review A, L020402 (2021)], an alternative strategy, the cluster expansion, was introduced. This approach naturally preserves internal and lattice symmetries and can more easily be extended to higher-order representations or longer-ranged interactions. We extend the cluster expansion to two-dimensional fermionic systems, and employ it to construct projected entangled-pair operator (PEPO) approximations of Gibbs states. We also discuss and benchmark different truncation schemes for multiplying layers of PEPOs together. Applying the resulting framework to a two-dimensional spinless fermion model with attractive interactions, we resolve a clear phase boundary at finite temperature.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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