论文标题
多体激子和valley互动的相关性在浓厚的电子掺杂WSE $ _2 $单层中
Many-body exciton and inter-valley correlations in heavily electron-doped WSe$_2$ monolayers
论文作者
论文摘要
在单层过渡金属元素化元素半导体中，当将光激发的电子孔对（激子）引入2D费米亚的移动载体海中时，多体相关性可以在光谱中表现出来。在低载体密度下，已充分记录了积极和负电荷的激子（$ x^\ pm $）的形成。但是，在WSE $ _2 $单层中，通常称为$ x^{ - \ prime} $的额外吸收共振，以高电子密度出现。它的起源尚不理解。在这里，我们通过高磁场至60〜t的静电门控WSE $ _2 $单层对$ x^{ - \ prime} $状态调查。 $ k'$ valley中最低的光学活性Landau水平的田间引起的填充和排空会导致相应光吸收的反复淬火。然而，令人惊讶的是，这些淬火伴随着$ k'$和$ k $ valleys的较高层兰道水平的吸收变化。这些结果不能在单粒子图片中进行调解，并演示了$ x^{ - \ prime} $ quasiparticle态的多体性质和valley相关性。
In monolayer transition-metal dichalcogenide semiconductors, many-body correlations can manifest in optical spectra when photoexcited electron-hole pairs (excitons) are introduced into a 2D Fermi sea of mobile carriers. At low carrier densities, the formation of positively and negatively charged excitons ($X^\pm$) is well documented. However, in WSe$_2$ monolayers, an additional absorption resonance, often called $X^{-\prime}$, emerges at high electron density. Its origin is not understood. Here we investigate the $X^{-\prime}$ state via polarized absorption spectroscopy of electrostatically-gated WSe$_2$ monolayers in high magnetic fields to 60~T. Field-induced filling and emptying of the lowest optically-active Landau level in the $K'$ valley causes repeated quenching of the corresponding optical absorption. Surprisingly, however, these quenchings are accompanied by absorption changes to higher-lying Landau levels in both $K'$ and $K$ valleys, which are unoccupied. These results cannot be reconciled within a single-particle picture, and demonstrate the many-body nature and inter-valley correlations of the $X^{-\prime}$ quasiparticle state.
