Three-Dimensional Nano-Sculpting Devices : Helical Diodes

Researchers at the RIKEN Center for Emergent Matter Science introduced a nanosculpting technique that carves three-dimensional devices directly from single crystals, featuring microscopic helices made from the magnetic crystal Co3Sn2S2. The team used a focused ion beam to remove material with submicron precision, producing twisted structures that act as switchable diodes.

The method relied on focused ion beam milling to sculpt curved, chiral geometries while preserving crystalline quality; experiments confirmed nonreciprocal electrical transport in the helices, where current favors one direction and reverses when magnetization or helix handedness is flipped. The team also observed that strong electrical pulses can switch the magnetization, linking shape, magnetism, and transport.

This approach shows geometry can directly control electron flow, enabling compact, low-power components for memory, logic and sensing; by treating curvature as a design parameter, manufacturers could pair topological or correlated materials with 3D forms to unlock new device functions.

Image Credit: RIKEN