AI 中文总结
本研究提出含z_L、z_H关联因子的量化框架，确定自旋自由度有效性为低能洪德关联的微观起源，经多轨道模型和真实材料验证，为洪德特征提供普适量化度量。
AI 中文摘要
洪德耦合J诱导的关联效应与哈伯德U完全不同，这会导致布林克曼-赖斯场景被违反，并因低能有效性出现双面相，其中能带重整化被限制在特征能量尺度以下。我们提出一个量化框架，通过两个关联因子捕捉低能有效性：本研究新引入的用于低能准粒子重整化的z_L和用于高能电荷涨落的z_H。z_L与z_H的差异反映了关联的洪德特征。通过建立关联因子与自旋、电荷磁化率的一一对应关系，我们确定自旋自由度有效性是低能有效性的微观起源。该框架在多轨道模型和真实材料中得到验证，为洪德特征提供了普适且量化的度量。
英文摘要
Hund's coupling $J$ induces fundamentally different correlation effects from Hubbard $U$. This leads to a violation of the Brinkman--Rice scenario and the emergence of a Janus-faced phase owing to its low-energy effectiveness, in which band renormalization is confined below a characteristic energy scale. We propose a quantitative framework to capture low-energy effectiveness through two correlation factors: $z_L$ for low-energy quasiparticle renormalization and $z_H$ for high-energy charge fluctuations, newly introduced in this study. The discrepancy between $z_L$ and $z_H$ reflects the Hund character of the correlation. By establishing a one-to-one correspondence between correlation factors and the spin and charge susceptibilities, we identify the spin-degree-of-freedom effectiveness as the microscopic origin of low-energy effectiveness. Our framework, validated across multiorbital models and real materials, provides a universal and quantitative measure of Hundness.
Comments5 pages, 3 figures in main, 6 figures in supplementary material
