2026-08-31 分子科学研究所
図１(a) 超高速赤外近接場光顕微鏡の模式図。
＜関連情報＞
- https://www.ims.ac.jp/news/2026/08/0831.html
- https://pubs.acs.org/nalefd/article-abstract/26/31/10446/5233769/Ultrafast-Nano-imaging-and-Optical-Control-of
hBN/WS2ヘテロ接合における双曲線フォノンポラリトンの超高速ナノイメージングと光制御 Ultrafast Nano-imaging and Optical Control of Hyperbolic Phonon Polaritons at hBN/WS2 Heterojunctions
Kazuki Kamada;Keisuke Shinokita;Fanyu Zeng;Ryo Kitaura;Kenji Watanabe;Takashi Taniguchi;Alexander Paarmann;Masahiro Shibuta;Takashi Kumagai;Jun Nishida
Nano Letters Published:July 27, 2026
DOI:https://doi.org/10.1021/acs.nanolett.6c02448
Abstract
Manipulating nanoscale light–matter interactions on ultrafast time scales is indispensable for future polaritonic devices. Hyperbolic phonon polaritons (HPhPs) in van der Waals materials enable deep subwavelength confinement of electromagnetic fields in the infrared region and long-distance propagation of polaritonic waves. However, achieving ultrafast imaging and optical control of HPhPs remains a major challenge. Here, we demonstrate the direct observation of transient modulation of HPhPs induced by local photocarrier generation in WS2/hBN heterostructures using ultrafast infrared scanning near-field optical microscopy. We implement grating-based spectral filtering of broadband near-field scattering to simultaneously achieve nanoscale and femtosecond spatiotemporal resolution together with fine spectral selectivity. This ultrafast nano-imaging technique reveals that photocarriers in WS2 modulate the polaritonic field amplitudes and wavelengths of HPhPs in hBN. Theoretical simulations corroborate that these changes arise from photoinduced changes in WS2 dielectric properties. This approach offers a versatile platform for exploring ultrafast polaritonic dynamics at the nanoscale.
