Talk about cool research.

New findings from the Marlan and Rosemary Bourns College of Engineering could lay the groundwork for the electronics industry to develop devices that overheat less, process information faster, and are more energy-efficient than today’s technology.

Department of Electrical and Computer Engineering graduate researcher Shucheng Guo and assistant professor Xi Chen and others recently published a paper investigating the thermal properties of magnons — quasiparticles — which act like a wave of tiny magnets flipping in a row within magnetic materials. Their research determined that magnons traveling through a specially synthesized crystalline material with certain atomic alignments lead to reduced magnon thermal conductivity as the nanoscale dimensions of the material are reduced, according to their “Size-dependent magnon thermal transport in a nanostructured quantum magnet” paper.

As manufacturers continue to reduce the size of electronic devices — think mobile phones and laptops — preventing such technologies from getting too hot, slowing down, and wearing out quickly over time becomes more and more critical.

“Proper nanoscale energy transport can prevent overheating, ensuring the reliability and longevity of microprocessors and other semiconductor devices,” Guo said.

The study of magnons primarily focuses on information processing and storage using currents of magnons. It is considered an emerging alternative to conventional electronics, which relies on currents of electrons. Spintronics is the study of electrons’ spin and their magnetic properties.

“Focusing on magnons instead leads to more efficient and faster processing than conventional devices that rely on electrons instead,” Guo said.

In addition, a better understanding of magnons’ behavior can lead to innovative ways to convert heat into other forms of energy, such as electrical energy.

“This can open new avenues for thermoelectric materials and devices,” Guo said. 

In their experiments, Guo, Chen, and others looked at the influence of “grain size” in a quantum magnet made of lanthanum copper oxide played in how magnons behaved. As the grain size was smaller than the average distance magnons travel between neighboring collisions, the thermal conductivity from magnons decreased. This decrease is due to scattering at the grain boundaries of the material,  an important phenomenon that had not been demonstrated experimentally before.

“As electronic devices continue to shrink in size, efficient thermal management at the nanoscale becomes essential,” Guo said.

Continued research into what is termed “magnon thermal transport” is important, Guo said, because it can lead to new energy-efficient devices, faster and more efficient information storage and transfer, and new ways to convert heat into useful energy.

“These findings are crucial for controlling magnon transport properties through nanoengineering and for applications in thermal management and quantum information processing,” he said.

Header image: Close-up of a scanning electron microscope image of the nanostructures of La₂CuO₄, which serve as quantum magnets (Image courtesy of Shucheng Guo).