Researchers at QUT, led by Professor Dongchen Qi from the School of Chemistry and Physics, have demonstrated control over a quantum effect with the potential to revolutionize battery-free device technology. The international team, collaborating with Nanyang Technological University, investigated the nonlinear Hall effect (NLHE) in the topological material bismuth telluride, discovering a method to harness its power for direct current generation from alternating signals. Unlike conventional energy conversion, this quantum version eliminates the need for diodes and other bulky components, paving the way for significantly smaller and more efficient devices. “This effect allows us to convert alternating signals straight into direct current, which is what’s needed to power electronic devices,” said Professor Qi, suggesting a future of self-powered sensors, wearable technology, and ultra-fast wireless networks. The study reveals that temperature controls the direction and strength of the generated voltage, opening doors for practical applications of this previously abstract quantum phenomenon.
“The NLHE is a sophisticated quantum phenomenon in condensed matter physics where a voltage is generated perpendicular to an applied alternating current, even in the absence of a magnetic field,” explained Professor Qi, highlighting the effect’s potential to bypass traditional energy conversion methods. The team’s investigation focused on bismuth telluride, a topological material exhibiting unusual electronic properties, and demonstrated the NLHE’s stability at room temperature—a critical step toward practical applications. Researchers discovered that the direction and intensity of the generated voltage are demonstrably controllable through temperature manipulation, with imperfections dominating at lower temperatures and crystal lattice vibrations taking precedence as the material warms. “Once you understand what’s happening inside the material, you can design devices to take advantage of it,” Professor Qi stated, emphasizing the transition from theoretical physics to tangible technology.
This newfound control over the NLHE opens doors for self-powered sensors, wearable technology, and ultra-fast components for future wireless networks, offering a pathway toward smaller, faster, and more efficient electronic devices. The findings are detailed in the paper, “Unraveling scattering contributions to the nonlinear Hall effect in topological insulator Bi2Te3,” published in Newton online.
The international team, a collaboration between QUT and Nanyang Technological University, discovered that imperfections within the material significantly influence the NLHE at lower temperatures, while the crystal lattice vibrations become the dominant factor as the material warms. This nuanced interplay between material defects and lattice dynamics allows for manipulation of the generated voltage, offering a pathway toward optimized energy-harvesting devices. Professor Xiao Renshaw Wang’s team’s work builds on the understanding that the NLHE converts alternating signals into direct current without conventional diodes.
The NLHE is a sophisticated quantum phenomenon in condensed matter physics where a voltage is generated perpendicular to an applied alternating current, even in the absence of a magnetic field.
