AI 中文总结
本文开发了共线磁系统中含EMC的第一性原理输运计算框架，揭示α-Fe电阻率T²项由EPC与EMC强相互作用主导，且该框架对K掺杂BaMn₂As₂的EMC强度计算与实验吻合，填补了磁性系统输运研究的空白。
AI 中文摘要
与电子-声子耦合（EPC）类似，电子-磁振子耦合（EMC）有望调控磁性材料的电子结构、输运性质，甚至非常规超导电性。然而，EPC现已可在第一性原理框架内常规处理，而EMC的定量描述（尤其是针对输运性质）仍难以实现，原因是缺乏对应的理论形式。因此，即便对单质铁而言，仅考虑EPC的计算会同时遗漏电阻率的大小及其T²项。这一长期存在的差异一直被归因于EMC，但此前缺乏直接计算证据，且潜在的输运机制也未明确。本文在多体微扰理论框架内，开发了适用于共线磁系统的EMC统一第一性原理形式，辅以带自旋的机器学习哈密顿量，补充了常规第一性原理方法无法直接获取的物理量。该框架首次实现了包含EMC效应的从头算输运计算。将其应用于铁磁性α-Fe，所得电子谱函数与此前研究一致；更重要的是，成功复现了电阻率的完整T²项，其系数与测量结果定量吻合，且揭示T²项并非如长期假设般仅由EMC导致，而是由EPC与EMC的强相互作用主导。将该方法拓展至反铁磁性K掺杂BaMn₂As₂，成功捕捉到角分辨光电子能谱（ARPES）观测到的磁振子诱导扭折，以及约3的大EMC强度，与实验测量结果相当，验证了该框架的通用性。本研究填补了磁性系统输运性质定量理解领域的长期空白，为研究磁振子介导现象提供了预测性基础。
英文摘要
In analogy to electron-phonon coupling (EPC), electron-magnon coupling (EMC) is expected to shape electronic structure, transport, and possibly unconventional superconductivity in magnetic materials. However, unlike EPC, which is now routinely treated within first-principles frameworks, a quantitative description of EMC, especially for transport, remains elusive because of the lack of theoretical formalism. Consequently, even for elemental iron, EPC-only calculations miss both the magnitude and the $T^2$ component of resistivity. This discrepancy has long been attributed to EMC, although direct computational evidence has been lacking and the underlying transport mechanism remains unresolved. Here we develop a unified first-principles formalism for EMC in collinear magnetic systems within many-body perturbation theory, complemented by machine-learning spinful Hamiltonians that supply quantities not directly accessible from conventional first-principles methods. Our framework enables ab initio transport calculations including EMC effects for the first time. Applied to ferromagnetic $α$-Fe, our approach yields electron spectral functions consistent with previous studies. More importantly, we recover the full $T^2$ component of resistivity with a coefficient in quantitative agreement with measurement and reveal that the $T^2$ component cannot be attributed solely to EMC, as has long been assumed, but is dominated by the strong EPC-EMC interplay. Extending to antiferromagnetic K-doped $\mathrm{BaMn_2As_2}$, our method captures the ARPES-observed magnon-induced kink and a large EMC strength of $\sim 3$ comparable to experimental measurements, demonstrating the generality of the framework. Our work closes a longstanding gap in the quantitative understanding of transport in magnetic systems and provides a predictive foundation for examining magnon-mediated phenomena.
Comments19 pages, 3 figures
