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Abstract Plasmon polaritons, or plasmons, are coupled oscillations of electrons and electromagnetic fields that can confine the latter into deeply subwavelength scales, enabling novel polaritonic devices. While plasmons have been extensively studied in normal metals or semimetals, they remain largely unexplored in correlated materials. In this paper, we report infrared (IR) nano-imaging of thin flakes of CsV3Sb5, a prototypical layered Kagome metal. We observe propagating plasmon waves in real-space with wavelengths tunable by the flake thickness. From their frequency-momentum dispersion, we infer the out-of-plane dielectric function$${{{{{{\boldsymbol{\epsilon }}}}}}}_{{{{{{\boldsymbol{c}}}}}}}$$ that is generally difficult to obtain in conventional far-field optics, and elucidate signatures of electronic correlations when compared to density functional theory (DFT). We propose correlation effects might have switched the real part of$${{{{{{\boldsymbol{\epsilon }}}}}}}_{{{{{{\boldsymbol{c}}}}}}}$$ from negative to positive values over a wide range of middle-IR frequencies, transforming the surface plasmons into hyperbolic bulk plasmons, and have dramatically suppressed their dissipation.
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Localized surface plasmon controlled chemistry at and beyond the nanoscale
Gaining valuable insight into chemistry-related fields, such as molecular and catalytic systems, surface science, and biochemistry, requires probing physical and chemical processes at the sub-nanoscale level. Recent progress and advancements in nano-optics and nano-photonics, particularly in scanning near-field optical microscopy, have enabled the coupling of light with nano-objects using surface plasmons with sub-nanoscale precision, providing access to photophysical and photochemical processes. Herein, this review highlights the basic concepts of surface plasmons and recent experimental findings of tip-assisted plasmon-induced research works and offers a glimpse into future perspectives.
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- Award ID(s):
- 1944796
- PAR ID:
- 10404942
- Publisher / Repository:
- American Institute of Physics
- Date Published:
- Journal Name:
- Chemical Physics Reviews
- Volume:
- 4
- Issue:
- 2
- ISSN:
- 2688-4070
- Page Range / eLocation ID:
- Article No. 021301
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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