Directing Thermal Energy: New Research with Magneto-Optical Materials and a Phase-Change Material Called GST Can Direct Heat

      An international research team led by Professor Koichi Okamoto and Dr. Shunsuke Murai from Osaka Metropolitan University's Graduate School of Engineering utilized magneto-optical materials combined with a phase-change material called GST to demonstrate that heat energy can be directed. The device was able to break Lorentz reciprocity. 

     Science X staff at Phys.org explain:

“Normally, a material absorbs and emits heat in a linked way: A surface that absorbs heat well at a certain wavelength and direction will also emit heat in the same way. This fundamental relationship, known as reciprocity, limits the ability to independently control heat absorption and heat emission.”

“But if absorption and emission could be separated, engineers could design devices that absorb heat from one direction while emitting it in another. By "steering" thermal energy, they could create more efficient thermal management, energy conversion, infrared sensing and thermal communication technologies.”

     The team created a device that can control the direction of heat radiation, switch the effect on and off, and remember its state even when the power is removed, essentially allowing heat to be programmed like data in a microchip.

"We made heat radiation behave in a smarter way," Murai explained. "Achieving these capabilities in a working model could enable a new generation of efficient infrared emitters, thermal-energy devices, sensors and photonic memory technologies."

     The new device is a big improvement over previous devices, having overcome some significant obstacles.

"Our ultimate goal is to develop compact devices that can actively control heat radiation, much like electronic circuits control the flow of electricity," Okamoto said. "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."

     The research was published in the journal Laser & Photonics Reviews.

 

  

References:

 

Researchers break a fundamental rule to create a new concept: Heat that can be directed and 'programmed'. Science X staff. Phys.org. July 7, 2026. Researchers break a fundamental rule to create a new concept: Heat that can be directed and 'programmed'

Reconfigurable Giant Nonreciprocity at Near-Normal Incidence via Phase-Change Magneto-Optical Metagratings. Ye Ming Qing, Yi Shen, Jun Wu, Shunsuke Murai, Zhaogang Dong, and Koichi Okamoto. Laser & Photonics Review. Vol. 20. No. 14. July 22, 2026. Reconfigurable Giant Nonreciprocity at Near‐Normal Incidence via Phase‐Change Magneto‐Optical Metagratings - Qing - Laser & Photonics Reviews - Wiley Online Library