论文标题

在存在竞争相互作用的情况下,从显微镜自由度观察到晶格汉密尔顿模型的重建

Reconstruction of the lattice Hamiltonian models from the observations of microscopic degrees of freedom in the presence of competing interactions

论文作者

Valleti, Sai Mani Prudhvi, Vlcek, Lukas, Ziatdinov, Maxim, Vasudevan, Rama K., Kalinin, Sergei V.

论文摘要

扫描探针和电子束成像技术的出现允许对原子和振动结构的原子和振动结构的微小细节进行定量研究。这些显微镜描述符依次与局部对称性破坏现象有关,代表了基础生成物理模型的随机表现。在这里,我们探索了哈密顿式模型中的交换积分的重建,并从显微镜自由度的观察结果中进行了两种相互作用的相互作用,并在广泛的参数温度空间中建立了此类分析的不确定性和可靠性。作为一项辅助任务,我们基于直方图聚类开发一种机器学习方法,以使用减少的描述符空间有效地预测相图。我们进一步证明,当由于沮丧的相互作用而定义很差时,重建可能远远超过相变和参数空间区域。这表明这种方法可以应用于凝结物理学的传统复杂问题,例如铁电松弛剂和形态相边界系统,自旋和簇玻璃,一旦已知与相关物理行为相关的局部描述符,量子系统就已经知道。

The emergence of scanning probe and electron beam imaging techniques have allowed quantitative studies of atomic structure and minute details of electronic and vibrational structure on the level of individual atomic units. These microscopic descriptors in turn can be associated with the local symmetry breaking phenomena, representing stochastic manifestation of underpinning generative physical model. Here, we explore the reconstruction of exchange integrals in the Hamiltonian for the lattice model with two competing interactions from the observations of the microscopic degrees of freedom and establish the uncertainties and reliability of such analysis in a broad parameter-temperature space. As an ancillary task, we develop a machine learning approach based on histogram clustering to predict phase diagrams efficiently using a reduced descriptor space. We further demonstrate that reconstruction is possible well above the phase transition and in the regions of the parameter space when the macroscopic ground state of the system is poorly defined due to frustrated interactions. This suggests that this approach can be applied to the traditionally complex problems of condensed matter physics such as ferroelectric relaxors and morphotropic phase boundary systems, spin and cluster glasses, quantum systems once the local descriptors linked to the relevant physical behaviors are known.

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