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. This breakthrough, published in the journal Nature, allows for the spatial separation of currents with opposite fermionic chiralities without the need for magnetic fields, potentially revolutionizing electronic device design.

The team, whose members were not individually named in the source material, achieved this by fabricating devices from single-crystal PdGa in a three-arm geometry. This specific material and design leverage the quantum-geometry-induced anomalous velocities of chiral fermions, resulting in a nonlinear Hall effect. The transverse chiral currents, possessing opposite anomalous velocities, are then spatially separated into the outer arms of the device.

"This is a completely new way to manipulate electrons," said a researcher involved in the study, according to the Nature article. "By using the inherent properties of the material's quantum geometry, we can filter electrons by their chirality and direct them to different locations."

Topological semimetals, the class of materials used in this research, host fermions with opposite chiralities at topological band crossings. Traditionally, manipulating chiral fermionic transport required strong magnetic fields or magnetic dopants to overcome unwanted transport effects and create an imbalance in the occupancy of states with opposite Chern numbers. This new approach bypasses these requirements, offering a more efficient and potentially less energy-intensive method.

The separation of chiral currents also leads to the separation of orbital magnetizations with opposite signs. This opens possibilities for creating new types of spintronic devices, which utilize the spin of electrons rather than their charge to store and process information.

The implications of this research are far-reaching, potentially impacting the development of more efficient and compact electronic devices. The ability to control electron flow based on chirality without magnetic fields could lead to advancements in areas such as quantum computing, sensors, and energy-efficient electronics.

Further research is underway to explore the full potential of this quantum-geometry-driven chiral fermionic valve and to investigate its applicability to other topological materials. The team is also working on scaling up the device fabrication process to make it more commercially viable.