AI 中文总结
研究二维材料光载流子动力学中激子相关性的作用，引入基于激子布洛赫方程的双粒子框架，应用于WSe₂单层，揭示不同弛豫途径，确立激子相关性为光载流子动力学关键机制。
AI 中文摘要
我们研究了激子相关性在塑造半导体中光激发载流子超快动力学方面的作用。传统方法在单粒子框架内描述弛豫，忽略了在能带边缘附近占主导的电子 - 空穴相关性。我们引入基于激子布洛赫方程（XBE）的双粒子框架，该框架捕捉载流子 - 声子散射并明确考虑激子形成。将此方法应用于非共振光激发的WSe₂单层，揭示了不同的载流子弛豫途径，与实验相符，表明形成了相关的非平衡态，确立了激子相关性是激子材料中光载流子动力学的关键机制。
英文摘要
We investigate the role of excitonic correlations in shaping the ultrafast dynamics of photoexcited carriers in semiconductors. Conventional approaches describe relaxation within single-particle frameworks, where electron-electron and electron-phonon scattering drive thermalization toward Fermi-Dirac distributions, neglecting electron-hole correlations that dominate near band edges. We introduce a two-particle framework based on excitonic Bloch equations (XBE) that captures carrier-phonon scattering and explicitly accounts for exciton formation. Applying this approach to non-resonantly photoexcited WSe$_2$ monolayers, we reveal qualitatively different carrier relaxation pathways: in contrast to state-of-the-art methods, XBE predict enhanced intervalley scattering and dominant carrier population in Q valleys over K valleys, in agreement with time-resolved ARPES experiments. Moreover, the momentum distribution of thermalized carriers is shaped by exciton wavefunctions rather than by Fermi-Dirac statistics, signaling the formation of a correlated nonequilibrium state. These results establish excitonic correlations as a key mechanism governing photocarrier dynamics in excitonic materials.
Comments14 pages, 5 figures
Journal refNano Letters 2026
DOI：10.1021/acs.nanolett.6c01651
