Coherent steering of nonlinear chiral valley photons with a synthetic Au–WS2 metasurface
Two-dimensional transition metal dichalcogenides (TMDCs) present extraordinary nonlinearities and direct bandgaps at the K and K′ valleys. These valleys can be optically manipulated through, for example, plasmon–valley-exciton coupling with spin-dependent photoluminescence. However, the weak coheren...
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Published in | Nature photonics Vol. 13; no. 7; pp. 467 - 472 |
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Main Authors | , , , , , , , , , , , |
Format | Journal Article |
Language | English |
Published |
London
Nature Publishing Group UK
01.07.2019
Nature Publishing Group |
Subjects | |
Online Access | Get full text |
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Summary: | Two-dimensional transition metal dichalcogenides (TMDCs) present extraordinary nonlinearities and direct bandgaps at the K and K′ valleys. These valleys can be optically manipulated through, for example, plasmon–valley-exciton coupling with spin-dependent photoluminescence. However, the weak coherence between the pumping and emission makes exploring nonlinear valleytronic devices based on TMDCs challenging. Here, we show that a synthetic metasurface, which entangles the phase and spin of light, can simultaneously enhance and manipulate nonlinear valley-locked chiral emission in monolayer tungsten disulfide (WS
2
) at room temperature. The second-harmonic valley photons, accessed and coherently pumped by light, with a spin-related geometric phase imparted by a gold (Au) metasurface, are separated and routed to predetermined directions in free space. In addition, the nonlinear photons with the same spin as the incident light are steered owing to the critical spin–valley-locked nonlinear selection rule of WS
2
in our designed metasurface. Our synthetic TMDC–metasurface interface may facilitate advanced room-temperature and free-space nonlinear, quantum and valleytronic nanodevices.
By entangling the phase and spin of light, a synthetic metasurface is shown to be able to coherently manipulate the valley-exciton-locked chiral emission in monolayer tungsten disulfide at room temperature. The findings will be of benefit to advanced room-temperature and free-space nonlinear, quantum and valleytronic nanodevices. |
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ISSN: | 1749-4885 1749-4893 |
DOI: | 10.1038/s41566-019-0399-1 |