Slow and highly confined plasmons observed in atomically thin TaS2
Abstract Extreme light confinement down to the atomic scale has been theoretically predicted for ultrathin, Ta-based transition metal dichalcogenides (TMDs). In this work, we report the observation of highly confined plasmons in 2H-TaS2 monolayers and bilayers via momentum-resolved electron energy l...
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| Main Authors: | , , , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Nature Portfolio
2025-07-01
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| Series: | Nature Communications |
| Online Access: | https://doi.org/10.1038/s41467-025-60814-1 |
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| Summary: | Abstract Extreme light confinement down to the atomic scale has been theoretically predicted for ultrathin, Ta-based transition metal dichalcogenides (TMDs). In this work, we report the observation of highly confined plasmons in 2H-TaS2 monolayers and bilayers via momentum-resolved electron energy loss spectroscopy (q-EELS), with a resolution of 0.0056 Å−1. Momentum-dispersed two-dimensional (2D) plasmon resonances were found to exhibit 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. Moreover, we observed 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, potentially enabling even further enhanced optical field confinements for this material at cryogenic temperatures. |
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| ISSN: | 2041-1723 |