Small parts found in modern electronic devices that control the flow of electrons are known as semiconductor devices. They are necessary to power a plethora of high-tech gadgets, like as computers, cell phones, car sensors, and state-of-the-art medical equipment. On the other hand, electron flow can be disrupted by contaminants in the material or temperature changes, leading to instability.
A semiconductor device made of aluminum-gallium-arsenide (AlGaAs) has recently been constructed by theoretical and experimental physicists from the Würzburg-Dresden Cluster of Excellence, ct.qmat—Complexity and Topology in Quantum Matter. The electron flow in this device is protected from interference by topological quantum phenomena. The prestigious journal Nature Physics has published a thorough account of this ground-breaking study.
All of the currents connecting the various contacts on the quantum semiconductor are immune to contaminants and other external disturbances because of the topological skin effect. This increases the semiconductor industry’s attraction towards topological devices. The Institute for Theoretical Solid State Physics at the Leibniz Institute for Solid State and Materials Research in Dresden (IFW) director and principal investigator of ct.qmat, Professor Jeroen van den Brink, explains, “They eliminate the need for the extremely high levels of material purity that currently drive up the costs of electronics manufacturing.”
Topological quantum materials are well-suited for high-power applications because of their remarkable robustness. Our quantum semiconductor possesses a unique mix of stability and high accuracy. This makes our topological gadget an exciting new choice for sensor engineering.
Making use of the topological skin effect opens up new possibilities for extremely tiny and high-performance electrical quantum devices. According to van den Brink, “Our topological quantum device measures about 0.1 millimeters in diameter, and can be scaled down even further with ease.” This work by the Dresden and Würzburg team of physicists is groundbreaking since they are the first to demonstrate the topological skin effect in a semiconductor material at the microscopic level. Three years ago, this quantum phenomenon was first shown at a macroscopic level, but only in an artificial metamaterial, not a natural one. Thus, this is the first time that a small, ultra-sensitive, and extremely durable semiconductor-based topological quantum gadget has been created.
Because the electrons in our quantum gadget are restricted to the edge, the topological skin effect protects the current-voltage relationship. The current flow is stable even when there are impurities in the semiconductor material, according to van den Brink. Furthermore, the contacts can pick up on even the smallest variations in voltage or current, he says. This is why the topological quantum gadget is so well adapted to the creation of tiny-diameter, high-precision sensors and amplifiers.
By strategically placing contacts and materials on an AlGaAs semiconductor device, it was possible to induce the topological effect in the presence of a strong magnetic field at extremely cold temperatures. Van den Brink says, “We really worked the topological skin effect out of the device.” The two-dimensional semiconductor structure was used by the physics team. The topological impact was made evident directly by measuring the electrical resistance at the contact edges, which was made possible by the arrangement of the contacts.
In Würzburg and Dresden, ct. qmat has been studying topological quantum materials since 2019. The team is interested in learning more about these materials’ remarkable behavior under severe circumstances, such as extremely low temperatures, high pressures, or strong magnetic fields.
The scientists at the two locations of the cluster have been working together consistently, which has also led to the latest success. The new quantum device was designed at the IFW and was a result of collaboration between Dresden’s theoretical and experimental researchers and theoretical physicists from Universität Würzburg. The device was tested in Dresden after it was manufactured in France. In order to use this phenomenon to further advance technical advancements, Jeroen van den Brink and his associates are currently devoting their time to investigating it in further detail.
