Scientists have discovered a new way to control unusual quantum phenomena. This could one day help power electronic devices without batteries.
An international research team led by Professor Dongchen Qi from the School of Chemical Physics at the Queensland University of Technology (QUT) and Professor Xiao Renshaw Wang from Singapore’s Nanyang Technological University has investigated the physics behind the nonlinear Hall effect (NLHE), a quantum phenomenon with great potential for future energy harvesting technologies.
Unlike the classical Hall effect, NLHE can convert alternating current electrical signals directly to direct current. This means energy from wireless communications and other ambient sources could potentially be converted into usable power without relying on traditional diodes or other bulky electronic components.
“NLHE is an advanced quantum phenomenon in condensed matter physics in which a voltage is generated perpendicular to an applied alternating current even in the absence of a magnetic field,” said Professor Qi.
“This effect allows alternating current signals to be converted directly into direct current, which is what is needed to power electronic devices. In principle, it could mean sensors or chips that draw energy from the environment and can operate without batteries.”
Quantum materials exhibit stable performance at room temperature
To better understand how this effect works, the researchers examined a high-quality topological material known for its unusual electronic behavior.
Their experiments showed that the nonlinear Hall effect is stable even at room temperature, an important step toward practical application outside the laboratory.
The research team also found that temperature plays a key role in determining both the strength and direction of the voltage generated by the material.
How defects and atomic vibrations control the effects
At low temperatures, small defects in the material have the greatest impact on quantum effects. As the temperature increased, the naturally occurring vibrations within the crystal structure became more important.
This change reverses the direction of the generated electrical signal, revealing a previously unseen mechanism controlling the phenomenon.
“Once we understand what’s going on inside the material, we can design devices that take advantage of it,” Professor Qi said.
“Then quantum effects will cease to be abstract and begin to become useful, supporting future applications from self-powered sensors and wearable technologies to ultra-fast components for next-generation wireless networks.”
The discovery provides new insights into how quantum materials work and could help researchers develop smaller, faster and more energy-efficient technologies to harvest power from their surroundings.
