Valley polarized relaxation and upconversion luminescence from Tamm-plasmon trion-polaritons with a MoSe2 monolayer
Valley polarized relaxation and upconversion luminescence from Tamm-plasmon trion-polaritons with a MoSe2 monolayer
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DOI：
10.1088/2053-1583/aa6ef2
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发表时间：
2017-06-01
期刊：
影响因子：
5.5
通讯作者：
Schneider, C.
中科院分区：
文献类型：
--
作者：
Lundt, N.;Nagler, P.;Schneider, C.
过渡金属二硫属化合物是研究纳米凝聚态系统中激子效应、自旋相关现象和基本光-物质耦合的理想实验平台。特别是，谷度的自由，这是唯一的这种直接带隙单层反转对称性破缺，增加了这些材料的根本利益。在这里，我们实现了一个Tamm-plasmon结构与嵌入的MoSe 2单层和研究极化激元准粒子的形成。建立了MoSe 2的Tamm-mode和trion共振之间的强耦合条件，在非共振光激发下从极化激元基态产生明亮的发光。我们证明，剪裁的单分子层的电动力学环境的结果在一个显着增加的谷极化。这种增强可能与时间分辨光致发光测量中所示的复合动力学变化有关。我们还观察到较低极化激元分支中共振激发极化激元态的强烈上转换发光。这种上转换的极化激元发光被示出为保持谷极化的trion极化激元，这铺平了道路，结合自旋谷物理和激子散射实验。
Transition metal dichalcogenides represent an ideal testbed to study excitonic effects, spin-related phenomena and fundamental light-matter coupling in nanoscopic condensed matter systems. In particular, the valley degree of freedom, which is unique to such direct band gap monolayers with broken inversion symmetry, adds fundamental interest in these materials. Here, we implement a Tamm-plasmon structure with an embedded MoSe2 monolayer and study the formation of polaritonic quasi-particles. Strong coupling conditions between the Tamm-mode and the trion resonance of MoSe2 are established, yielding bright luminescence from the polaritonic ground state under non-resonant optical excitation. We demonstrate, that tailoring the electrodynamic environment of the monolayer results in a significantly increased valley polarization. This enhancement can be related to change in recombination dynamics shown in time-resolved photoluminescence measurements. We furthermore observe strong upconversion luminescence from resonantly excited polariton states in the lower polariton branch. This upconverted polariton luminescence is shown to preserve the valley polarization of the trion-polariton, which paves the way towards combining spin-valley physics and exciton scattering experiments.