It’s a rule that makes thermal energy difficult to control in ways we might like to, and although workarounds have been found before, they’re inefficient and volatile<\/a>.<\/p>\n In a new study published in Laser & Photonics Reviews<\/a> and carried out by an international team of researchers, we may have a way to separate absorption and emission to achieve programmable heat.<\/p>\n The innovation is based on the manipulation of light using a magnetic field: the direction of the heat emission can therefore be controlled, the manipulation can be switched on and off, and the system can even remember its state while powered off.<\/p>\n “We made heat radiation behave in a smarter way,” says<\/a> physicist Shunsuke Murai, from Osaka Metropolitan University in Japan.<\/p>\n “Achieving these capabilities in a working model could enable a new generation of efficient infrared emitters, thermal energy devices, sensors, and photonic memory technologies.”<\/p>\n The device the researchers imagined is called a metagrating. It combines a magneto-optical material that adjusts the behavior of absorbed heat when hit by a magnetic field<\/a>, and a phase-change material that acts as a memory bank.<\/p>\n If you’re a physical media fan, you might be interested to know that the phase-change material here \u2013 which can switch between amorphous (disordered) and crystalline (ordered) states \u2013 is Ge<\/a>2<\/a>\u2062Sb<\/a>2<\/a>\u2062Te<\/a>5<\/a>, an alloy of germanium, antimony, and tellurium also used in rewritable CDs and DVDs<\/a>.<\/p>\n That ‘grating’ is important too. Tiny, carefully designed ridges would trap and channel the incoming light, making it more manageable than previous systems, and more viable as a practical solution.<\/p>\n By adjusting the angle of the light, the strength of the magnetic field, and the physical dimensions of the grating, the researchers could ‘program’ the desired heat absorption behavior<\/a> \u2013 without the same reciprocal heat emissions.<\/p>\n “By simply adjusting the incident angle, the operating wavelength of the nonreciprocal absorber can be continuously tuned across a broad spectral range,” write<\/a> the researchers.<\/p>\n That flexibility and versatility mean the programmable device would have a wide range of potential applications. This is all theoretical physics and math at the moment, though \u2013 albeit well-calculated and modeled \u2013 and the next stage is to actually build a prototype.<\/p>\n “This work establishes a rigorous physical framework for active non-reciprocal thermal control, paving the way for next-generation chip-scale thermal photonics,” write<\/a> the researchers in their published paper.<\/p>\n The published study describes<\/a> decoupling heat emission<\/a> from heat absorption as a “critical frontier in modern thermal photonics”, though it’s worth pointing out that the research focused mainly on absorption \u2013 the emission part was largely assumed rather than explored in detail.<\/p>\n Requiring an external magnetic field to control the properties of the device and its material adds a few extra wrinkles too, though there’s no reason why this should present a significant stumbling block to further development.<\/p>\n There are of course a vast number of systems and technologies that make use of light and heat and their manipulation<\/a>, and these findings could be useful across many of them. It’s another reminder that the laws of physics are there to be broken<\/a>.<\/p>\n Related: <\/strong>Startling Exception Discovered to 200-Year-Old Law of Physics<\/strong><\/a><\/p>\n “Our ultimate goal is to develop compact devices that can actively control heat radiation, much like electronic circuits control the flow of electricity,” says<\/a> physicist Koichi Okamoto, from Osaka Metropolitan University.<\/p>\n “Such devices could be used in smarter infrared sensors, more efficient energy systems, and new types of photonic memory that store information using light and heat instead of electrical charges.”<\/p>\n The research has been published in Laser & Photonics Reviews<\/a>.<\/p>\n This article was fact-checked by Michael Irving<\/a> and edited by Rebecca Dyer<\/a>. While we pride ourselves on our process, we are only human. If you spot a mistake, please let us know<\/a>.<\/p>\n![\"YouTube](\"https:\/\/www.europesays.com\/us\/wp-content\/uploads\/2026\/07\/https:\/\/media.zenfs.com\/en\/sciencealert_160\/642df3ebc8083841eee3826ad5face7f.jpeg\"\/)
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