Ordinary light scatters in all directions, like water from a shattered glass. But in some crystals, light waves can bunch together into narrow beams and flow in a single direction, like water in a trough. Physicists studied such a material: layered vanadium oxide α-V2O5.

In this crystal, atoms vibrate differently along and across the layers. As a result, light entering the crystal behaves unusually: waves traveling in different directions cancel each other out, leaving only one beam. It resembles a thin jet that doesn't spread. The researchers captured these beams using an ultra-high-resolution infrared microscope.

This property is called polariton canalization. A polariton is a hybrid of a light wave and atomic vibrations. In α-V2O5, these mixed waves spontaneously form channels without any additional material processing. Previously, this required complex devices or modifying the crystal itself.

Such light behavior promises new possibilities for nano-optics: light can be controlled at scales hundreds of times smaller than the thickness of a human hair. The beams do not scatter and follow a precise path, like rails for light.