Wen Te, Zhang Weidong, Liu Shuai, Hu Aiqin, Zhao Jingyi, Ye Yu, Chen Yang, Qiu Cheng-Wei, Gong Qihuang, Lu Guowei
State Key Laboratory for Mesoscopic Physics, Frontiers Science Center for Nano-optoelectronics, and Collaborative Innovation Center of Quantum Matter, School of Physics, Peking University, Beijing 100871, China.
Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China.
Sci Adv. 2020 May 20;6(21):eaao0019. doi: 10.1126/sciadv.aao0019. eCollection 2020 May.
Monolayer transition metal dichalcogenides have intrinsic spin-valley degrees of freedom, making it appealing to exploit valleytronic and optoelectronic applications at the nanoscale. Here, we demonstrate that a chiral plasmonic antenna consisting of two stacked gold nanorods can modulate strongly valley-polarized photoluminescence (PL) of monolayer MoS in a broad spectral range at room temperature. The valley-polarized PL of the MoS using the antenna can reach up to ~47%, with approximately three orders of PL magnitude enhancement within the plasmonic nanogap. Besides, the K and K' valleys under opposite circularly polarized light excitation exhibit different emission intensities and directivities in the far field, which can be attributed to the modulation of the valley-dependent excitons by the chiral antenna in both the excitation and emission processes. The distinct features of the ultracompact hybrid suggest potential applications for valleytronic and photonic devices, chiral quantum optics, and high-sensitivity detection.
单层过渡金属二硫属化物具有固有的自旋谷自由度，这使得在纳米尺度上开发谷电子学和光电子学应用具有吸引力。在此，我们证明由两个堆叠的金纳米棒组成的手性等离子体天线能够在室温下的宽光谱范围内强烈调制单层MoS的谷极化光致发光（PL）。使用该天线的MoS的谷极化PL可达约47%，在等离子体纳米间隙内PL强度增强约三个数量级。此外，在相反圆偏振光激发下的K和K'谷在远场表现出不同的发射强度和方向性，这可归因于手性天线在激发和发射过程中对谷依赖激子的调制。这种超紧凑混合体的独特特性表明其在谷电子学和光子器件、手性量子光学以及高灵敏度检测方面具有潜在应用。
