德国马克斯-普朗克高分子研究所Heejae Kim课题组研究了二维光谱中的模式分辨非局域电子-声子耦合。该研究于2025年4月8日发表在《自然—物理学》杂志上。

电子-声子耦合是凝聚态物理学的基础，控制着传统和量子材料中的各种物理现象和性质。研究组提出并演示了二维电子-声子耦合光谱，该光谱可以直接提取特定声子模式和不同电子能量的电子-声子偶联矩阵元素。使用这种技术，他们测量了单个声子模式的电子-声子耦合强度的电子能量依赖性。

这使人们能够识别出区分非本地Su-Schrieffer-Heeger型联轴器和本地Holstein型联轴器的不同特征。将这种方法应用于甲基铵碘化铅钙钛矿，研究组揭示了两个明显声子模式的电子-声子耦合的特别不同的性质，例如温度依赖性或各向异性。该方法提供了对电子-声子耦合微观起源的见解，并在声子介导的超快控制材料特性中具有潜在的应用。

附：英文原文

Title: Mode-resolved, non-local electron–phonon coupling in two-dimensional spectroscopy

Author: Qu, Sheng, Sharma, Vishal K., Geuchies, Jaco J., Grechko, Maksim, Bonn, Mischa, Pientka, Falko, Kim, Heejae

Issue&Volume: 2025-04-08

Abstract: Electron–phonon coupling is fundamental to condensed-matter physics, governing various physical phenomena and properties in both conventional and quantum materials. Here we propose and demonstrate two-dimensional electron–phonon coupling spectroscopy that can directly extract the electron–phonon coupling matrix elements for specific phonon modes and different electron energies. Using this technique, we measure the electron energy dependence of the electron–phonon coupling strength for individual phonon modes. It allows us to identify distinct signatures distinguishing non-local Su–Schrieffer–Heeger-type couplings from local Holstein-type couplings. Applying this methodology to a methylammonium lead iodide perovskite, we reveal particularly different properties, for example, temperature dependence or anisotropy, of the electron–phonon couplings of two pronounced phonon modes. Our approach provides insights into the microscopic origin of the electron–phonon coupling and has potential applications in phonon-mediated ultrafast control material properties.

DOI: 10.1038/s41567-025-02861-5

Source: https://www.nature.com/articles/s41567-025-02861-5