Valley-addressable polaritons in atomically thin semiconductors
Valley-addressable polaritons in atomically thin semiconductors
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DOI：
10.1038/nphoton.2017.125
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发表时间：
2017-08-01
期刊：
影响因子：
35
通讯作者：
Tartakovskii, A. I.
中科院分区：
文献类型：
--
作者：
Dufferwiel, S.;Lyons, T. P.;Tartakovskii, A. I.
在过渡金属二硫属化物（TMD）单层中，电子自旋锁定到谷自由度，已经看到这些材料成为谷电子学中有前途的平台（1，2）。当嵌入光学微腔中时，TMD中激子跃迁的大振子强度允许形成部分光部分物质准粒子的极化激元（3-7）。在这里，我们报告说，极化激元在MoSe 2显示出有效的保留谷赝自旋对比他们在这种材料中的激子和trions。我们发现，谷赝自旋保留的程度依赖于极化激元态中的光子、激子和三电子分数。这使我们能够得出结论，在极化激子制度，腔修改激子弛豫抑制损失的谷赝自旋。谷可寻址激子极化激元和trion极化激元提供了强大的谷极化状态的基础上嵌入在光子结构和谷依赖的非线性极化激元-极化激元相互作用的TMD谷电子器件的潜力。
The locking of the electron spin to the valley degree of freedom in transition metal dichalcogenide (TMD) monolayers has seen these materials emerge as a promising platform in valleytronics(1,2). When embedded in optical microcavities, the large oscillator strengths of excitonic transitions in TMDs allow the formation of polaritons that are part-light part-matter quasiparticles(3-7). Here, we report that polaritons in MoSe2 show an efficient retention of the valley pseudospin contrasting them with excitons and trions in this material. We find that the degree of the valley pseudospin retention is dependent on the photon, exciton and trion fractions in the polariton states. This allows us to conclude that in the polaritonic regime, cavity-modified exciton relaxation inhibits loss of the valley pseudospin. The valley-addressable exciton-polaritons and trion-polaritons presented here offer robust valley-polarized states with the potential for valleytronic devices based on TMDs embedded in photonic structures and valley-dependent nonlinear polariton-polariton interactions.