论文标题
拓扑的机器学习光谱指标
Machine learning spectral indicators of topology
论文作者
论文摘要
拓扑材料发现已成为冷凝物理物理学的重要领域。虽然理论分类框架已被用来识别数千种候选拓扑材料,但对材料拓扑的实验确定通常会带来重大的技术挑战。 X射线吸收光谱(XAS)是一种广泛使用的材料表征技术,对原子的局部对称性和化学键合敏感,通过拓扑量子化学理论(TQC),它们与带拓扑密切相关。此外,作为局部结构探针,XAS在实验和计算之间具有很高的定量一致性,这表明来自计算光谱的见解可以有效地为实验提供信息。在这项工作中,我们利用计算的X射线吸收接近边缘结构(XANES)光谱,超过10,000个无机材料来训练神经网络(NN)分类器,该分别从XANES签名中直接预测拓扑类别,分别从XANES签名获得拓扑类别,分别获得89%和93%的拓扑和93%。此外,我们使用相应的实验和计算XANES光谱获得一致的分类,以进行少量测量化合物。鉴于XAS设置的简单性及其与多模式样本环境的兼容性,提议的机器学习功能增强的XAS拓扑指标有可能发现更广泛的拓扑材料类别,例如不可裂解的化合物和非晶体材料,并且可能会进一步为磁场拓扑相位式的现场驱动现象,例如,诸如磁场拓扑相位的现象。
Topological materials discovery has emerged as an important frontier in condensed matter physics. While theoretical classification frameworks have been used to identify thousands of candidate topological materials, experimental determination of materials' topology often poses significant technical challenges. X-ray absorption spectroscopy (XAS) is a widely-used materials characterization technique sensitive to atoms' local symmetry and chemical bonding, which are intimately linked to band topology by the theory of topological quantum chemistry (TQC). Moreover, as a local structural probe, XAS is known to have high quantitative agreement between experiment and calculation, suggesting that insights from computational spectra can effectively inform experiments. In this work, we leverage computed X-ray absorption near-edge structure (XANES) spectra of more than 10,000 inorganic materials to train a neural network (NN) classifier that predicts topological class directly from XANES signatures, achieving F$_1$ scores of 89% and 93% for topological and trivial classes, respectively. Additionally, we obtain consistent classifications using corresponding experimental and computational XANES spectra for a small number of measured compounds. Given the simplicity of the XAS setup and its compatibility with multimodal sample environments, the proposed machine learning-augmented XAS topological indicator has the potential to discover broader categories of topological materials, such as non-cleavable compounds and amorphous materials, and may further inform field-driven phenomena in situ, such as magnetic field-driven topological phase transitions.