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arXiv 2602.21695cond-mat.str-el
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将矩阵积态与平均场理论相结合以捕捉准一维铜基氧化物中的磁序

Combining matrix product states and mean-field theory to capture magnetic order in quasi-1D cuprates

Center for Molecular Modeling, Ghent University(根特大学分子建模中心);Department of Physics and Astronomy, Ghent University(根特大学物理与天文学系)

Quentin Staelens, Daan Verraes, Daan Vrancken, Tom Braeckevelt, Jutho Haegeman, Veronique Van Speybroeck

AI总结:

本研究通过结合矩阵积态与平均场理论,揭示了准一维铜基氧化物中磁序的形成机制,解决了纯一维模型无法解释实验观测的问题。

摘要:

我们利用密度泛函理论、下折技术以及张量网络模拟,采用多步方法研究准一维强关联材料。下折过程得到有效的多带Hubbard模型,能够捕捉电子跃迁与局部库仑相互作用之间的竞争,这对系统的低能性质至关重要。所得多带Hubbard模型通过矩阵积态求解。应用于Sr₂CuO₃、SrBaCuO₃和Ba₂CuO₃时,这种纯粹一维处理无法产生长程磁序,与实验观测的磁序相矛盾。为解释这一行为,我们通过自洽平均场方案引入链间耦合,扩展了多步方法。这种结合方法稳定了有限的阶梯磁化,提供了与实验一致的磁序描述。对于Sr₂CuO_{3.5}和SrCuO₂,我们也测试了适用于阶梯材料的方案,但发现这些材料不适用于该方案,因为链内跃迁参数的幅度较小。

英文摘要:

We study quasi-one-dimensional strongly correlated materials using a multi-step approach based on density functional theory, downfolding techniques, and tensor-network simulations. The downfolding procedure yields effective multiband Hubbard models that capture the competition between electron hopping and local Coulomb interactions relevant to the system's low-energy properties. The resulting multiband Hubbard models are solved using matrix product states. Applied to Sr$_2$CuO$_3$, SrBaCuO$_3$, and Ba$_2$CuO$_3$, this purely one-dimensional treatment yields no long-range magnetic order, in contrast to the magnetic ordering observed experimentally. To account for this behavior, we extend the multi-step approach by incorporating interchain couplings through a self-consistent mean-field scheme. This combined approach stabilizes finite staggered magnetizations, providing a consistent description of magnetic order in agreement with experiment. For Sr$_2$CuO$_{3.5}$ and SrCuO$_2$, we also tested an approach proposed for ladder materials, however, we find that these materials are not well suited for this approach due to the small magnitude of the intraladder hopping parameters.

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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