论文标题
通过光吸收来测量固体中相互作用切割的浆果曲率和量子度量
Measurement of interaction-dressed Berry curvature and quantum metric in solids by optical absorption
论文作者
论文摘要
浆果曲率和量子度量通常描述了动量空间中Bloch状态的量子几何特性。在相互作用和混乱的逼真的间隙材料中，使Bloch状态不是一个可行的起点，我们通过在有限温度下引入着装的浆果曲率和量子指标来概括这些概念，其中可以将多体相互作用的效果触及。这些量是从线性或圆极化电场引起的电荷极化敏感性中提取的，这些电场可以通过动量分辨的激子或红外吸收率来测量其光谱函数。作为一个具体的例子，我们在存在杂质散射的情况下研究了Chern绝缘子，其结果表明，量子几何特性受到能量隙的保护，以防止多体相互作用。
The quantum geometric properties of a Bloch state in momentum space are usually described by the Berry curvature and quantum metric. In realistic gapped materials where interactions and disorder render the Bloch state not a viable starting point, we generalize these concepts by introducing dressed Berry curvature and quantum metric at finite temperature, in which the effect of many-body interactions can be included perturbatively. These quantities are extracted from the charge polarization susceptibility caused by linearly or circularly polarized electric fields, whose spectral functions can be measured from momentum-resolved exciton or infrared absorption rate. As a concrete example, we investigate Chern insulators in the presence of impurity scattering, whose results suggest that the quantum geometric properties are protected by the energy gap against many-body interactions.
