Researchers have discovered that thin films of elemental bismuth exhibit the so-called non-linear Hall effect, which could be applied in technologies for the controlled use of terahertz high-frequency signals on electronic chips. Bismuth combines several advantageous properties not found in other systems to date, as the team reports. Particularly: the quantum effect is observed at room temperature. The thin-layer films can be applied even on plastic substrates and could therefore be suitable for modern high-frequency technology applications.