Magnetic-field-induced splitting and polarization of monolayer-based valley exciton polaritons
Magnetic-field-induced splitting and polarization of monolayer-based valley exciton polaritons
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DOI：
10.1103/physrevb.100.121303
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发表时间：
2019-09-27
影响因子：
3.7
通讯作者：
Schneider, C.
中科院分区：
文献类型：
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作者：
Lundt, N.;Klaas, M.;Schneider, C.
原子薄的过渡金属二硫族化合物晶体非常适合研究光-物质耦合、极化和磁场效应的相互作用。在这个快速通信中，我们研究了mosse2单层中激子极化子的形成，该单层集成在一个完全成熟的单片微腔中。由于极化共振的线宽较窄，我们能够直接研究在磁场存在下出现的混合光物质共振的谷塞曼分裂。在失谐为-54.5 meV（13.5%的物质构成下极化子分支）时，我们发现下极化子分支发生了0.36 meV的塞曼分裂，这与激子g因子3.94 +/- 0.13直接相关。值得注意的是，我们发现6 T的磁场足以在我们的极化子系统中诱导出显著的谷极化15%，在9 T时接近30%。这种极化子（基态）的圆极化度超过了等磁场强度下激子库的极化约50%，这清楚地暗示了在亚阈值、波动主导的强耦合系统中存在谷依赖玻色子刺激。
Atomically thin crystals of transition-metal dichalcogenides are ideally suited to study the interplay of light-matter coupling, polarization, and magnetic field effects. In this Rapid Communication, we investigate the formation of exciton polaritons in a MoSe2 monolayer, which is integrated in a fully grown, monolithic microcavity. Due to the narrow linewidth of the polaritonic resonances, we are able to directly investigate the emerging valley Zeeman splitting of the hybrid light-matter resonances in the presence of a magnetic field. At a detuning of -54.5 meV (13.5% matter constituent of the lower polariton branch), we find a Zeeman splitting of the lower polariton branch of 0.36 meV, which can be directly associated with an excitonic g-factor of 3.94 +/- 0.13. Remarkably, we find that a magnetic field of 6 T is sufficient to induce a notable valley polarization of 15% in our polariton system, which approaches 30% at 9 T. This circular polarization degree of the polariton (ground) state exceeds the polarization of the exciton reservoir for equal magnetic field magnitudes by approximately 50%, which is a clear hint of valley-dependent bosonic stimulation in our strongly coupled system in the subthreshold, fluctuation-dominated regime.