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Updated: Nov 21, 2025
13:56
Probe Type II Band Alignment in One-Dimensional Van Der Waals Heterostructures Using First-Principles Calculations
Published on: October 12, 2019
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Plasmons in the van der Waals charge-density-wave material 2H-TaSe2
Chaoyu Song1,2, Xiang Yuan1,3, Ce Huang1
1State Key Laboratory of Surface Physics and Department of Physics, Fudan University, 200433, Shanghai, China.
Nature Communications
|January 16, 2021
Summary
Researchers demonstrated tunable localized plasmons in 2D tantalum diselenide (2H-TaSe2), a correlated material. These plasmons exhibit unique behavior near charge-density-wave excitations, offering new possibilities for 2D material applications.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanophotonics
Background:
- Plasmons in two-dimensional (2D) materials are crucial for advanced optical and electronic applications.
- Experimental studies of 2D plasmons beyond graphene are hindered by material limitations.
- Correlated 2D materials offer unique platforms for exploring novel plasmonic phenomena.
Purpose of the Study:
- To experimentally demonstrate localized plasmons in a correlated 2D charge-density-wave (CDW) material, 2H-TaSe2.
- To investigate the tunability and spectral range of these plasmons.
- To explore the interplay between plasmons and CDW excitations.
Main Methods:
- Experimental realization of localized plasmons in 2H-TaSe2.
- Spectroscopic characterization across terahertz to telecom wavelengths.
- Investigation of plasmon dispersion and its dependence on material thickness and dielectric environment.
- Temperature-dependent measurements to probe CDW interactions.
Main Results:
- Localized plasmons were successfully demonstrated in 2H-TaSe2, covering a broad spectral range (40 μm to 1.55 μm).
- Plasmon resonance is tunable via material thickness and dielectric environment.
- Plasmon dispersion flattens at large wave vectors due to interband screening.
- Anomalous temperature dependence of plasmons was observed in the CDW phase, showing peak broadening and asymmetry near CDW excitations.
Conclusions:
- 2H-TaSe2 supports tunable localized plasmons with broad spectral coverage.
- Intrinsic screening effects significantly influence 2D plasmon dispersion.
- The interaction between plasmons and CDW excitations leads to unique spectral features.
- This work opens new avenues for plasmonics in 2D correlated materials.
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