AI 中文总结
研究利用d波反铁磁体，通过马格努斯展开和弗洛凯对角化，借助线性偏振非共振光，经量子度量介导带隙重整化驱动轨道选择性铁谷相，可分离、控制并读出量子度量效应。
AI 中文摘要
在量子材料中，将量子度量与贝里曲率分离仍然是一个核心挑战，因为这两个几何量几乎总是共存且难以区分其贡献。我们表明，实哈密顿量的贝里曲率严格消失的d波反铁磁体构成了克服这一障碍的理想平台。利用马格努斯展开和精确弗洛凯对角化，我们证明线性偏振非共振光通过纯量子度量介导的带隙重整化驱动轨道选择性铁谷相，且任何阶都无贝里曲率贡献。轨道选择性源于跳跃各向异性，它在$d_{xz}$和$d_{yz}$轨道之间产生明显的度量各向异性，能通过量子度量解析表达带隙减小。由此产生的谷隙差异提供了量子度量的直接定量测量，可通过自旋分辨光电子能谱和光泵浦-探测光谱获取。这确立了d波反铁磁体为一个纯净、可调谐的平台，其中量子度量效应可被分离、由光偏振控制并通过谷偏振读出。
英文摘要
Isolating the quantum metric from the Berry curvature remains a central challenge in quantum materials, as the two geometric quantities nearly always coexist and their contributions are difficult to disentangle. We show that d-wave altermagnets, whose real Hamiltonian possesses strictly vanishing Berry curvature, constitute an ideal platform for overcoming this obstacle. Using the Magnus expansion and exact Floquet diagonalization, we demonstrate that linearly polarized off-resonant light drives an orbital-selective ferrovalley phase through a purely quantum-metric--mediated band-gap renormalization, with no Berry curvature contribution at any order. The orbital selectivity originates from the hopping anisotropy, which generates a pronounced metric anisotropy between the $d_{xz}$ and $d_{yz}$ orbitals, and the gap reduction is expressed analytically in terms of the quantum metric. The resulting valley gap difference provides a direct, quantitative measure of the quantum metric, accessible to spin-resolved ARPES and optical pump-probe spectroscopy. This establishes d-wave altermagnets as a pristine, tunable platform in which quantum metric effects can be isolated, controlled by light polarization, and read out through valley polarization.
Comments11 pages, 3 figures
