trustmebro.to/r/…
✓ checked
trust me, bro:
here is the receipt.
the claim

The real part of the permittivity of metals can be negative for some frequencies in the visible part of the spectrum.

the verdict
SUPPORTED
the evidence backs this
Recorded sources
5 sources for · 0 against

Counts group repeated records of the same source within each side. They do not measure evidence strength or source independence.

Is it true that the real part of the permittivity of metals can be negative for some frequencies in the visible part of the spectrum?

Yes. Metals can exhibit a negative real part of permittivity for certain visible-spectrum frequencies, a property foundational to plasmonics.

Verdict: SUPPORTED · 5 sources for, 0 against · Last checked

The analysis

The retrieved papers consistently support the well-established physical principle that metals and plasmonic materials can possess a negative real part of permittivity at optical and visible frequencies due to collective free-electron oscillations (plasmon resonance).

Evidence for · 5
Electron confinement-induced plasmonic breakdown in metals.
2024
Get citation
P, D., S, R., D, R., S, B., A, I., M, G., A, B., IV, B., VM, S., & B, S. (2024). Electron confinement-induced plasmonic breakdown in metals.. doi.org. https://doi.org/10.1126/sciadv.adr2596

See more details
More for · 4
Plasmonics of non-noble metals.
2026
Get citation
M, H., M, F., V, B., P, D., & T, Š. (2026). Plasmonics of non-noble metals.. doi.org. https://doi.org/10.1039/d6ra02381a

Optical and Plasmonic Properties of High-Electron-Density Epitaxial and Oxidative Controlled Titanium Nitride Thin Films.
2025
Get citation
I, C., S, C., W, A., S, N., M, L., C, M., V, C., RS, K., J, M., T, C., J, Y., E, C., JD, S., S, A., MD, M., J, Z., L, Z., G, H., & D, K. (2025). Optical and Plasmonic Properties of High-Electron-Density Epitaxial and Oxidative Controlled Titanium Nitride Thin Films.. doi.org. https://doi.org/10.1021/acs.jpcc.4c06969

Computational design and geometry-driven modeling of TiN-based plasmonic metasurface absorbers.
2026
Get citation
A, N., AH, A., & W, S. (2026). Computational design and geometry-driven modeling of TiN-based plasmonic metasurface absorbers.. doi.org. https://doi.org/10.1038/s41598-026-43764-6

Materials with Negative Permittivity or Negative Permeability-Review, Electrodynamic Modelling, and Applications.
2025
Get citation
J, K. (2025). Materials with Negative Permittivity or Negative Permeability-Review, Electrodynamic Modelling, and Applications.. doi.org. https://doi.org/10.3390/ma18020423

What does the evidence say?

The retrieved papers consistently support the well-established physical principle that metals and plasmonic materials can possess a negative real part of permittivity at optical and visible frequencies due to collective free-electron oscillations (plasmon resonance).

also asked as
  • Can the real part of permittivity in metals be negative at visible light frequencies?
  • Is it true that metal permittivity has a negative real part in the visible spectrum?
  • Do some frequencies of visible light give metals a negative real permittivity?
  • Are there visible frequencies where the real part of metal permittivity is negative?
Receipt History
Anyone with this link can read the claim and its public receipt, including any personal information in that text. Open permanent receipt.
Check your own claim
Challenge the receipt
Requests are recorded for review. This does not start an automatic check or guarantee a response time.

See the evidence timeline

Citation formatting by citeproc-js (Frank Bennett) and the Citation Style Language project. Source and licenses.

This receipt is an automated verdict against our published method · not an opinion about any author or publication.
Terms · Privacy · How verdicts work