Transition metal dichalcogenides with intrinsic spin–valley degrees of freedom hold great potentials for applications in spintronic and valleytronic devices. MoS₂ monolayer possesses two inequivalent valleys in the Brillouin zone, with each valley coupling selectively with circularly polarized photons. The degree of valley polarization (DVP) is a parameter to characterize the purity of valley‐polarized photoluminescence (PL) of MoS₂ monolayer. Usually, the detected values of DVP in MoS₂ monolayer show achiral property under optical excitation of opposite helicities due to reciprocal phonon‐assisted intervalley scattering process. Here, it is reported that valley‐polarized PL of MoS₂ can be tailored through near‐field interaction with plasmonic chiral metasurface. The resonant field of the chiral metasurface couples with valley‐polarized excitons, and tailors the measured PL spectra in the far‐field, resulting in observation of chiral DVP of MoS₂‐metasurface under opposite helicities excitations. Valley‐contrast PL in the chiral heterostructure is also observed when illuminated by linearly polarized light. The manipulation of valley‐polarized PL in 2D materials using chiral metasurface represents a viable route toward valley‐polaritonic devices.

中文翻译：

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利用超级手性近场量身定制MoS2山谷偏振光致发光

具有内在自旋-谷自由度的过渡金属二硫属化合物在自旋电子器件和谷电子器件中具有巨大的应用潜力。MoS ₂单层在布里渊区具有两个不等价的波谷，每个波谷选择性地与圆偏振光子耦合。谷底偏振度（DVP）是表征MoS ₂单层的谷底偏振光致发光（PL）纯度的参数。通常，在MoS ₂单层中DVP的检测值由于相互的声子辅助的intervalley散射过程而在相反螺旋的光激发下表现出非手性。据报道，MoS _2的谷极化PL可以通过与等离子手征形表面的近场相互作用来定制。手性超表面的共振场与谷极化激子耦合，并在远场中定制测得的PL光谱，从而在相反的螺旋激发下观察到MoS _2-金属表面的手性DVP 。当用线性偏振光照射时，也观察到手性异质结构中的波谷对比PL。使用手性超颖表面在2D材料中操纵波谷极化PL代表了通向波谷极化设备的可行途径。