What this work contributes
Directly compares directional absorption and emission in a resonant photonic structure incorporating magneto-optic InAs. An applied magnetic field makes these quantities unequal in the same directional channel, providing experimental evidence for nonreciprocal thermal optics.
Where the evidence stops
This concerns spectral-directional reciprocity, not a violation of thermodynamics or momentum conservation. The reported observables are optical and thermal properties, not propulsion force.
Keep the conditions with the result
- Measured / modeled quantity
- Directional spectral absorptivity and emissivity
- Reported scale
- Mid-infrared resonances; magnetic-field comparisons include −1 T and +1 T.
- Conditions
- Heated photonic sample; emissivity measurements at 50, 100 and 150 °C.
- Evidence context
- Measurement and modeling compared by the authors; independent replication not assessed.
- Design use
- Ground a nonreciprocal-materials track in measured optical response before deriving force predictions.
- Review access
- Full-paper methods and figures inspected through an author-hosted copy.
Original source
Komron J. Shayegan, Souvik Biswas, Bo Zhao, Shanhui Fan, Harry A. Atwater. Direct observation of the violation of Kirchhoff’s law of thermal radiation. Nature Photonics 17, 891–896 (2023).
DOI: 10.1038/s41566-023-01261-6
How we use it
This record belongs to Driven & thermal fields. Its evidence label describes the cited work, not the maturity of a Metric Flight device. Follow the original methods, corrections and conditions before transferring a result to a different geometry or scale.
Editorial note reviewed 19 October 2026. AI assisted research discovery and synthesis. Citation metadata and claims were checked against primary publication or institutional records; full-text access varies. Read the source for the complete method.