An active metasurface enhanced with moir\'e ferroelectricity

• DOI: 10.48550/arxiv.2405.11159
• Publication Date: 2024-01-01
• Authors: Kim, Dong Seob; Xiao, Chengxin; Dominguez, Roy C.; Liu, Zhida; Abudayyeh, Hamza; Lee, Kyoungpyo; Mayorga-Luna, Rigo; Kim, Hyunsue; Watanabe, Kenji; Taniguchi, Takashi; Shih, Chih-Kang; Miyahara, Yoichi; Yao, Wang; Li, Xiaoqin
• Keywords: Condensed Matter - Materials Science; Condensed Matter - Mesoscale and Nanoscale Physics; Mesoscale and Nanoscale Physics (cond-mat.mes-hall); Materials Science (cond-mat.mtrl-sci); FOS: Physical sciences

Semiconductor moiré systems, characterized by their periodic spatial light emission, unveil a new paradigm of active metasurfaces. Here, we show that ferroelectric moiré domains formed in a twisted hexagonal boron nitride (t-hBN) substrate can modulate light emission from an adjacent semiconductor MoSe$_2$ monolayer, enhancing its functionality as an active metasurface. The electrostatic potential at the surface of the t-hBN substrate provides a simple way to confine excitons in the MoSe$_2$ monolayer. The excitons confined within the domains and at the domain walls are spectrally separated due to a pronounced Stark shift. Moreover, the patterned light emission can be dynamically controlled by electrically gating the ferroelectric domains, introducing a novel functionality beyond conventional semiconductor moiré systems. Our findings chart an exciting pathway for integrating nanometer-scale moiré ferroelectric domains with various optically active functional layers, paving the way for advanced nanophotonic applications.