Luo, YueMao, NannanDing, DapengChiu, Ming-HuiJi, XiangWatanabe, KenjiTaniguchi, TakashiTung, VincentPark, HongkunKim, PhilipKong, JingWilson, William L.2023-10-102023-01-23Luo, Yue, Nannan Mao, Dapeng Ding, Ming-Hui Chiu, Xiang Ji, Kenji Watanabe, Takashi Taniguchi et al. "Electrically switchable anisotropic polariton propagation in a ferroelectric van der Waals semiconductor." Nat. Nanotechnol. 18, no. 4 (2023): 350-356. DOI: 10.1038/s41565-022-01312-z1748-33871748-3395https://nrs.harvard.edu/URN-3:HUL.INSTREPOS:37377196Tailoring of the propagation dynamics of exciton-polaritons in two-dimensional quantum materials has shown extraordinary promise to enable nanoscale control of electromagnetic fields. Varying permittivities along crystal directions within layers of material systems, can lead to an in-plane anisotropic dispersion of polaritons. Exploiting this physics as a control strategy for manipulating the directional propagation of the polaritons is desired and remains elusive. Here, we explore the in-plane anisotropic exciton-polariton propagation in SnSe, a group-IV monochalcogenide semiconductor which forms ferroelectric domains and exhibits room-temperature excitonic behavior. Exciton-polaritons are launched in SnSe multilayer plates, with their propagation dynamics and dispersion studied. This propagation of exciton-polaritons allows for nanoscale imaging of the in-plane ferroelectric domains. Finally, we demonstrate the electric switching of the exciton-polaritons in the ferroelectric domains of this complex vdW system. The study suggests that systems like group-IV monochalcogenides could serve as excellent ferroic platforms for actively reconfigurable polaritonic optical devices.en-USElectrical and Electronic EngineeringCondensed Matter PhysicsGeneral Materials ScienceBiomedical EngineeringAtomic and Molecular Physics, and OpticsBioengineeringJournal Article2023-10-1010.1038/s41565-022-01312-z