标题： 由暗态介导的双激子极化子耦合 显示英文标题

标题： Biexciton-polariton coupling mediated by dark states

摘要： 多激子关联决定了纳米结构材料的光诱导响应，特别是在光限制增强相互作用时。这里使用多维相干光谱来量化半导体微腔中的双激子和激子极化子动力学。一量子和二量子光谱主要由极化子相关贡献主导，还包含一个与极化子相关的偏振依赖性双激子特征，其幅度和光谱坐标取决于腔模式与激子共振之间的失谐。比较使用共线和非共线实验几何结构获得的光谱表明，激发波矢对这种行为没有显著影响。测量的能量色散和腔增强与未耦合的双激子或双极化子不兼容。为了解释这些测量结果，引入了一个间接的双激子-光子耦合模型，其中双激子由库仑耦合到极化子的明亮激子部分的暗激子形成。该模型解决了以前在半导体微腔中报告的双激子不一致观察结果，并可推广到任何光学暗激子参与光-物质相互作用的材料。我们的结果表明了一种通过强耦合系统中的多激子关联来获取长寿命暗激子的机制。 显示英文摘要

摘要： Multi-exciton correlations shape the photo-induced response of nanostructured materials, particularly when interactions are enhanced by light confinement. Here multidimensional coherent spectroscopy is used to quantify biexciton and exciton-polariton dynamics in a semiconductor microcavity. One- and two-quantum spectra, which are dominated by polariton-related contributions, also include a polarization-dependent biexciton feature whose magnitude and spectral coordinates depend on the detuning between the cavity mode and the exciton resonance. Comparison of spectra acquired using collinear and noncollinear experimental geometries indicates that excitation wavevector plays no significant role in this behavior. The measured energy dispersion and cavity enhancement are not compatible with uncoupled biexcitons or bipolaritons. To explain the measurements, an indirect biexciton-photon coupling model is introduced whereby biexcitons are formed from dark excitons that Coulomb couple to the bright-exciton fraction of the polaritons. The model addresses inconsistent observations of biexcitons previously reported in semiconductor microcavities and is generalizable to any material where optically dark excitons contribute to light-matter interaction. Our results suggest a mechanism to access long-lived dark excitons through multi-exciton correlations in strongly coupled systems.