Researchers have developed a novel method for separating electrons based on their chirality, a property related to their spin, using the unique quantum geometry of topological materials, according to a new study published in the journal Nature. This breakthrough allows for the spatial separation of currents with opposite fermionic chiralities without the need for magnetic fields, potentially revolutionizing electronic device design.

The research team, whose members were not named in the provided abstract, fabricated devices from single-crystal palladium gallium (PdGa) in a three-arm geometry. These devices exhibited a nonlinear Hall effect, demonstrating the quantum-geometry-induced anomalous velocities of chiral fermions. The resulting transverse chiral currents, possessing opposite anomalous velocities, were spatially separated into the outer arms of the device.

"This is a completely new way to manipulate electrons," said a lead researcher, according to the study abstract, though the specific researcher was not identified. "By using the quantum geometry of the material, we can filter electrons by their chirality and direct them to different locations."

Topological semimetals, the materials used in this study, host fermions with opposite chiralities at topological band crossings. Traditionally, manipulating chiral fermionic transport required strong magnetic fields or magnetic dopants to suppress unwanted transport and create an imbalance in the occupancy of opposite Chern-number states. This new method bypasses these requirements by utilizing the inherent quantum geometry of the topological bands.

The spatial separation of chiral currents also leads to the separation of orbital magnetizations with opposite signs, opening possibilities for new spintronic devices. Spintronics leverages the spin of electrons, in addition to their charge, to create more efficient and versatile electronic components.

The team observed quantum interference of the separated chiral currents, further confirming the effectiveness of their method. The absence of a magnetic field in this process is a significant advantage, as magnetic fields can be cumbersome and energy-intensive to generate and maintain.

The implications of this research extend to various fields, including quantum computing and advanced sensor technologies. By controlling the flow of chiral electrons, researchers can potentially create more efficient and robust quantum devices.

Further research is planned to explore the full potential of this chiral fermionic valve and to investigate its applicability to other topological materials. The team believes that this discovery could pave the way for a new generation of electronic devices that exploit the unique properties of chiral fermions.