Generalized Wilson loop method for nonlinear light-matter interaction
Generalized Wilson loop method for nonlinear light-matter interaction
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DOI：
10.1038/s41535-022-00472-4
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发表时间：
2022-06
影响因子：
5.7
通讯作者：
Hua Wang;Xiuyu Tang;Haowei Xu;Ju Li;Xiaofeng Qian
中科院分区：
文献类型：
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作者：
Hua Wang;Xiuyu Tang;Haowei Xu;Ju Li;Xiaofeng Qian
非线性光与物质相互作用作为超快光学、体光伏、非线性光学传感和成像以及纠缠光子的高效生成的核心，传统上一直通过第一性原理理论方法和态求和方法进行研究。然而，这种间接方法经常遇到能带简并和光学零点的发散以及收敛问题和状态求和时计算成本高的问题。在这里，以位移矢量和位移电流电导率张量为例，我们提出了一种规范不变的广义方法，通过在广义威尔逊环中表示带间贝里曲率、量子度量和位移矢量，可以有效、直接地计算非线性光学响应。这种广义的威尔逊循环方法避免了上述繁琐的挑战，并且允许轻松实现和高效计算。更重要的是，威尔逊环表示基于量子几何张量和量子几何势提供了非线性光学过程和响应的简洁几何解释，并且可以轻松应用于研究其他激发态响应。
Nonlinear light–matter interaction, as the core of ultrafast optics, bulk photovoltaics, nonlinear optical sensing and imaging, and efficient generation of entangled photons, has been traditionally studied by first-principles theoretical methods with the sum-over-states approach. However, this indirect method often suffers from the divergence at band degeneracy and optical zeros as well as convergence issues and high computation costs when summing over the states. Here, using shift vector and shift current conductivity tensor as an example, we present a gauge-invariant generalized approach for efficient and direct calculations of nonlinear optical responses by representing interband Berry curvature, quantum metric, and shift vector in a generalized Wilson loop. This generalized Wilson loop method avoids the above cumbersome challenges and allows for easy implementation and efficient calculations. More importantly, the Wilson loop representation provides a succinct geometric interpretation of nonlinear optical processes and responses based on quantum geometric tensors and quantum geometric potentials and can be readily applied to studying other excited-state responses.