ZAP // From-e-2
The nonlinear Hall effect can be used to power devices without using batteries
Scientists have identified a new way to control an unusual quantum phenomenon that could one day help power electronic devices without batteries.
A team of researchers discovered how microscopic imperfections and atomic vibrations can be used to control a powerful quantum effect in an advanced material.
This effect canand transform alternating electrical signals present not environment directly on the type of current that electronic devices needwithout resorting to traditional components.
As the temperature changes, the signal can even reverse directionoffering scientists a new way to tune device performance.
The international team of researchers, led by Dongchen Qiprofessor da Queensland University of Technology (QUT), e Xiao Renshaw Wangfrom Nanyang Technological University in Singapore, studied the physics behind the so-called nonlinear Hall effect (NLHE), a quantum phenomenon with significant potential for future energy harvesting technologies.
The results of their study were presented in a recently published in the journal Newton.
Unlike the classic Hall effectthe NLHE can convert alternating electrical signals directly into direct current. This means that energy from wireless transmissions or other environmental sources could, in principle, be transformed into usable electricity without relying on conventional diodes or other bulky electronic components.
“NLHE is a sophisticated quantum phenomenon in physics of condensed matter, in which a voltage perpendicular to an applied alternating current is generated, even in the absence of a magnetic field”, said Qi in QUT.
“This effect allows us to convert alternating signals directly into direct current, which is what we need to power electronic devices. In principle, this means sensors or chips capable of work without batteriestaking energy from the environment that surrounds them.”
To better understand how this effect works, researchers analyzed a high quality topological materialknown for its unusual electronic behavior.
The experiments showed that the nonlinear Hall effect remains stable even at room temperaturean important step towards practical applications outside the laboratory.
The team also discovered that temperature plays an essential role in determining both the intensity and direction of the electrical voltage produced by the material.
At lower temperatures, small imperfections inside the material were the factor with the greatest influence on the quantum effect. As the temperature increased, the natural vibrations of the crystal structure became more important.
This change led to a reversal of direction of the electrical signal generated, revealing a control mechanism for the phenomenon that had not been observed until now. “When you understand what’s happening inside the material, you can design devices that take advantage of that,” says Qi.
“It is at this moment that quantum effects cease to be abstract and they are starting to become useful — supporting future applications ranging from autonomous sensors and wearable technology to ultrafast components for next-generation wireless networks.”
