Steering valley-polarized emission of monolayer MoS2 sandwiched in plasmonic antennas

Te Wen; Weidong Zhang; Shuai Liu; Aiqin Hu; Jingyi Zhao; Yu Ye; Yang Chen; Cheng-Wei Qiu; Qihuang Gong; Guowei Lu

doi:10.1126/sciadv.aao0019

Steering valley-polarized emission of monolayer MoS₂ sandwiched in plasmonic antennas

Sci Adv. 2020 May 20;6(21):eaao0019. doi: 10.1126/sciadv.aao0019. eCollection 2020 May.

Authors

Te Wen^{1

2}, Weidong Zhang^{1

2}, Shuai Liu¹, Aiqin Hu¹, Jingyi Zhao¹, Yu Ye¹, Yang Chen³, Cheng-Wei Qiu³, Qihuang Gong^{1

2}, Guowei Lu^{1

2}

Affiliations

¹ 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.
² Collaborative Innovation Center of Extreme Optics, Shanxi University, Taiyuan, Shanxi 030006, China.
³ Department of Electrical and Computer Engineering, National University of Singapore, Singapore 117583, Singapore.

Abstract

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 MoS₂ in a broad spectral range at room temperature. The valley-polarized PL of the MoS₂ 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.

Copyright © 2020 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).