2024/11/12 by Meng Zhao, Do, Hue T. B., Zhao, Meng +20 · 1 citation
Engineering · Materials Science · Physics and Astronomy · #2D Materials and Applications #FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Molecular Junctions and Nanostructures #Quantum optics and atomic interactions
paper · pdf · doi:10.48550/arxiv.2411.07572
openalex publication_date 2024/11/12 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Extreme light confinement down to the atomic scale has been theoretically predicted for ultrathin, Ta-based transition metal dichalcogenides (TMDs). In this work, we experimentally demonstrate in 2H-TaS2 monolayers and bilayers a lateral confinement ratio up to 300 at large wave vectors of q = 0.15 Å-1, and slow light behaviour with a group velocity ∼ 10-4c. Quantitative momentum-resolved electron energy loss spectroscopy (q-EELS) with a momentum resolution of 0.0056 Å-1 was used as a platform for the nanoscale optical measurements. With it, momentum-dispersed, two-dimensional (2D) plasmon resonances were experimentally observed, showing a transition from 2D to 3D Coulomb interaction in the high-momentum regime, equivalent to light confinement volumes of 1-2 nm3. Remarkably, the resonant modes do not enter the electron-hole continuum, predicting even further enhanced optical field confinements for this material at cryogenic temperatures.