Room-temperature valley coherence in a polaritonic system
Room-temperature valley coherence in a polaritonic system
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DOI：
10.1038/s41467-019-09490-6
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发表时间：
2019-04-03
影响因子：
16.6
通讯作者：
Vamivakas, A. N.
中科院分区：
文献类型：
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作者：
Qiu, L.;Chakraborty, C.;Vamivakas, A. N.
谷电子学的新兴领域旨在相干地操纵电子和/或空穴的谷赝自旋作为信息承载自由度（DOF）。单层过渡金属二硫属化物由于其强束缚激子、简并谷和与光子的无缝界面而成为室温谷电子学的有希望的候选者。虽然激子结合能表明室温谷相干性应该是可能的，但迄今为止还难以实现。一个潜在的解决方案涉及基于2D材料激子的半光半物质腔极化激元的形成。最近发现，腔极化激元可以继承谷自由度。在这里，我们展示了室温谷相干谷极化激元嵌入单层的钨二硒在单片电介质腔。由激子-腔耦合引入的不受退相干影响的额外衰减路径是保持室温谷相干的关键。这些观察为实用的谷电设备铺平了道路。
The emerging field of valleytronics aims to coherently manipulate an electron and/or hole's valley pseudospin as an information bearing degree of freedom (DOF). Monolayer transition metal dichalcogenides, due to their strongly bound excitons, their degenerate valleys and their seamless interfacing with photons are a promising candidate for room temperature valleytronics. Although the exciton binding energy suggests room temperature valley coherence should be possible, it has been elusive to-date. A potential solution involves the formation of half-light, half-matter cavity polaritons based on 2D material excitons. It has recently been discovered that cavity polaritons can inherit the valley DOF. Here, we demonstrate the room temperature valley coherence of valley-polaritons by embedding a monolayer of tungsten diselenide in a monolithic dielectric cavity. The extra decay path introduced by the exciton-cavity coupling, which is free from decoherence, is the key to room temperature valley coherence preservation. These observations paves the way for practical valleytronic devices.