Electrons travel losslessly along edges in new topological model
Ballistic electron channels, where electrons travel without scattering, are a key feature of two-dimensional topological materials. In these systems, electrons can move along edges or surfaces with minimal energy loss because scattering events - such as those caused by impurities or lattice vibrations - are largely suppressed. Ballistic conduction typically occurs when the mean free path of electrons exceeds the dimensions of the conductor. This transport regime is critical for next-generation, energy-efficient circuits and quantum computing devices.
Topological materials, including topological insulators, possess special conducting edge states protected by quantum properties. These edge channels allow electrons to flow robustly, maintaining performance even with structural defects or disorder. Such properties make these materials attractive candidates for stable, ultra-fast electronics and scalable quantum computation.
The new framework from Juelich builds on the classical ballistic charge transport theory established by Rolf Landauer, which assumed electrons only enter or exit a channel at its ends. Unlike the idealized Landauer model, the Juelich approach allows electrons to enter and exit at any point along the channel, reflecting the reality of experimental systems.
Dr Kristof Moors, first author of the study, emphasized, "This allows us to describe the behaviour of such edge channels for the first time in a way that reflects what actually happens in experiments." Moors continued, "Our theory also provides distinct signatures that can be used to identify lossless, ballistic current flow and distinguish it from conventional charge transport."
The research demonstrates that the current in the two-dimensional material fundamentally changes due to the ballistic channel's presence. The model predicts voltage distributions observable by nanoscale probes or multi-tip scanning tunnelling microscopes. These new measurement techniques make it possible to experimentally distinguish between ballistic and lossy currents - an essential step toward confirming these exotic conduction channels and applying them to future device architectures.
Research Report:Distributed Current Injection into a One-Dimensional Ballistic Edge Channel
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