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, detailed in a recent Nature publication, paves the way for new electronic devices that manipulate electron flow without the need for magnetic fields, potentially leading to more efficient and compact technologies.

The team, whose members are not named in the provided source material, demonstrated this effect using a three-armed device made from single-crystal palladium gallium (PdGa). This material is a topological semimetal, meaning it possesses unique electronic properties arising from its band structure. These materials host fermions with opposite chiralities at topological band crossings. Unlike previous methods that rely on strong magnetic fields or magnetic doping to control electron flow, this new approach utilizes the intrinsic quantum geometry of the material to filter electrons by chirality into distinct states.

According to the study, the quantum geometry induces anomalous velocities in chiral fermions, leading to a nonlinear Hall effect. This effect spatially separates transverse chiral currents with opposite anomalous velocities into the outer arms of the device. These chiral currents, existing in opposing Chern number states, also carry orbital magnetizations with opposite signs. The mesoscopic phase coherence of these currents was also observed.

The significance of this research lies in its potential to overcome limitations of existing spintronic devices. Spintronics, which utilizes the spin of electrons rather than their charge, offers advantages such as lower power consumption and higher data processing speeds. However, many spintronic devices require magnetic fields to manipulate electron spin, which can be bulky and energy-intensive. This new method offers a way to control electron chirality without magnetic fields, potentially leading to smaller, more energy-efficient spintronic devices.

The researchers believe this discovery could have a significant impact on the development of future electronic technologies. By harnessing the quantum geometry of topological materials, it may be possible to create new types of electronic components, such as chiral filters and spin-based transistors, that are more efficient and versatile than current devices. Further research is needed to explore the full potential of this technology and to develop practical applications.