This material just broke the 165-year-old law of thermodynamics
What's the story
A team of researchers from Penn State University has made a groundbreaking discovery by violating Kirchhoff's 165-year-old law of thermal radiation. The law, proposed in 1860, states that a body's ability to emit heat is equal to its ability to absorb it under similar conditions. The team's work could transform solar energy harvesting, infrared sensing, and heat management technologies beyond previously imagined thermodynamic efficiency limits.
Breakthrough
The metamaterial that defies physics
The research team created a two-micrometer-thick metamaterial made of five engineered semiconductor layers. This new material emits more heat in one direction than it absorbs, creating a phenomenon called nonreciprocal thermal radiation. The team achieved a nonreciprocity contrast of 0.43 across a broad 10-micron infrared wavelength range, far surpassing previous records and making their discovery even more significant.
Mechanism
Implications for solar energy and infrared sensing
The thin-film metamaterial design allows semiconductor layers to interact with a magnetic field, enabling heat to flow preferentially in one direction. This property makes it transferable to different surfaces, paving the way for real-world device integration. Experts believe this could redefine thermal technologies by making solar panels more efficient at capturing energy and infrared sensors more accurate at detecting heat.